AutoCAD Quiz: Lengthen Command
10 questions · exam conditions
0:00
Lengthen CommandQuestion 1 of 10

Two separate lines are currently 8080 units and 120120 units long. In one LENGTHEN session, a designer chooses Percent, enters 62.5%62.5\%, and then selects one endpoint of each line.

What are the final lengths of the two lines?

They become 5050 units and 7575 units, respectively.
They become 62.562.5 units and 62.562.5 units, respectively.
They become 3030 units and 7070 units, respectively.
They become 130130 units and 170170 units, respectively.
← Back to quizzes

AutoCAD Quiz

AutoCAD Quiz: Lengthen Command

Practice Lengthen Command in AutoCAD with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Lengthen Command, giving you a quick way to practice the rules, question types, and explanations that matter most for AutoCAD.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

Two separate lines are currently 8080 units and 120120 units long. In one LENGTHEN session, a designer chooses Percent, enters 62.5%62.5\%, and then selects one endpoint of each line.

What are the final lengths of the two lines?

  1. They become 5050 units and 7575 units, respectively. (correct answer)
  2. They become 62.562.5 units and 62.562.5 units, respectively.
  3. They become 3030 units and 7070 units, respectively.
  4. They become 130130 units and 170170 units, respectively.
Explanation: When you see a question about LENGTHEN with the Percent option, remember one key rule: the percentage you enter applies proportionally to each selected object's current length — it does not set a fixed absolute length. A value below 100%100\% shortens the object; above 100%100\% lengthens it. Here, entering 62.5%62.5\% means each line is scaled to 62.5%62.5\% of its original length. For the 8080-unit line: 80×0.625=5080 \times 0.625 = 50 units. For the 120120-unit line: 120×0.625=75120 \times 0.625 = 75 units. That confirms A as the correct answer — the lines become 5050 and 7575 units, respectively. Choice B is a classic trap: it treats the percentage as an absolute target length, as if both lines are simply set to 62.562.5 units. That's not how Percent mode works. Choice C reflects a subtraction mistake — perhaps subtracting 62.562.5 from each original length (80−62.5≈3080 - 62.5 \approx 30... loosely) rather than multiplying by the percentage. Choice D goes in the opposite direction entirely, suggesting the lines grew, which would only happen if the entered percentage exceeded 100%100\%. A helpful way to remember this: think of LENGTHEN Percent like a scaling factor. 62.5%=0.62562.5\% = 0.625, and you multiply — never subtract, never treat it as absolute. When studying AutoCAD modify commands, always clarify what the input value represents (absolute length vs. percentage vs. delta) for each sub-option, since mixing these up is the most common source of errors on exam questions like this.

Question 2

Before editing a line, a drafter starts LENGTHEN. At the initial prompt, the drafter selects the line directly instead of choosing Delta, Percent, Total, or Dynamic.

What should the drafter expect from that selection?

  1. AutoCAD repeats the most recent length change and modifies the nearest endpoint.
  2. AutoCAD enters Dynamic mode and attaches the nearest endpoint to the cursor.
  3. AutoCAD reports the line's current length and leaves the line unchanged. (correct answer)
  4. AutoCAD opens Properties and highlights the line's read-only length value.
Explanation: When working with LENGTHEN, it helps to understand that the command has two distinct phases: first it informs, then it modifies. AutoCAD is designed so that selecting an object at the initial prompt — before you've specified a method like Delta, Percent, Total, or Dynamic — simply reports that object's current length. This is a deliberate "look before you touch" safeguard built into the command. That's exactly why C is correct. Clicking the line at the opening prompt triggers a read-only response: AutoCAD displays the current length (and included angle, for arcs) in the command line and then re-issues the prompt. The line itself is untouched. You're essentially asking AutoCAD, "How long is this?" before deciding how to change it. A describes behavior that doesn't exist in LENGTHEN — the command has no memory of a "most recent length change" that it automatically repeats on a new selection. B confuses the initial selection with the Dynamic sub-option, which only activates when you explicitly type DY at the prompt; simply clicking the object never drops you into dynamic dragging mode. D is a plausible-sounding trap because the Properties palette does show length, but LENGTHEN never opens Properties — it's a standalone editing command, not a palette trigger. A good study habit here: whenever a command asks you to select an object before you've configured how to act on it, AutoCAD is almost always gathering information, not making a change. Remember — inform first, modify second.

Question 3

A closed rectangular polyline has a perimeter of 4848 units. A designer attempts to make its perimeter 5252 units by choosing LENGTHEN Total, entering 5252, and selecting one of its segments.

Why does this workflow not produce the requested perimeter?

  1. LENGTHEN cannot modify any polyline segment individually; only the STRETCH command can resize a polyline.
  2. LENGTHEN does not modify closed objects, so the closed polyline remains unchanged regardless of the entered value. (correct answer)
  3. LENGTHEN Total requires an entry smaller than the current length when shortening, so the correct entry would have been 44.
  4. LENGTHEN Total resizes only the selected segment to 5252 units without adjusting the remaining segments or the overall perimeter.
Explanation: Whenever you see a question about LENGTHEN on the AutoCAD exam, the first thing to recall is the command's fundamental limitation: it cannot operate on closed objects at all. This single rule unlocks the entire question. LENGTHEN is designed to extend or shorten open objects — lines, open polylines, arcs, and similar geometry. When you select a closed polyline, AutoCAD simply ignores the operation. It doesn't matter which option you use (Total, Delta, Percent, or Dynamic) or what value you enter — the closed polyline remains completely unchanged. That's exactly what happens in the scenario: the designer's workflow fails not because of a wrong value, but because the target object is closed. Answer B correctly identifies this root cause. Looking at the distractors: A is wrong because LENGTHEN can modify open polyline segments individually — the restriction is specifically about closed objects, not polylines in general. C is wrong on two levels: first, LENGTHEN Total sets the absolute final length of the selected segment (so 5252 would be a valid entry for a longer segment), and second, even a perfectly valid entry won't matter since the closed polyline blocks the command entirely. D is wrong because it describes a plausible misunderstanding of how Total works, but the real issue isn't about unaffected segments — the command doesn't execute at all on a closed object. As a study tip, remember this pairing: LENGTHEN = open objects only; PEDIT or STRETCH are your tools when you need to modify closed polyline geometry. Closed-object restrictions are a favorite exam trap.

Question 4

A circular arc has radius 55 units and an included angle of 60∘60^\circ. A drafter chooses LENGTHEN Delta, enters a length increment of 22 units without choosing the Angle suboption, and selects one endpoint of the arc.

Approximately what is the arc's new included angle?

  1. 62.0∘62.0^\circ, because the entered length is interpreted directly as degrees.
  2. 71.5∘71.5^\circ, because the length increment is divided by the arc's diameter.
  3. 82.9∘82.9^\circ, because the length increment corresponds to about 22.9∘22.9^\circ. (correct answer)
  4. 120.0∘120.0^\circ, because a positive delta doubles the original included angle.
Explanation: Whenever you see a LENGTHEN Delta question involving an arc, remember that entering a plain length value (without the Angle suboption) always adds or subtracts arc length in drawing units — never degrees directly. To find the new angle, start from first principles. The original arc length is calculated with L=rθL = r\theta, where θ\theta is in radians. For a 55-unit radius and 60∘60^\circ included angle: θ=60×π180≈1.0472 rad\theta = 60 \times \frac{\pi}{180} \approx 1.0472 \text{ rad}, so L=5×1.0472≈5.236L = 5 \times 1.0472 \approx 5.236 units. Adding the 22-unit delta gives a new arc length of 7.2367.236 units. Converting back: θnew=7.2365≈1.4472 rad≈82.9∘\theta_{new} = \frac{7.236}{5} \approx 1.4472 \text{ rad} \approx 82.9^\circ. That confirms C is correct — the increment of 22 units corresponds to an angular increase of about 22.9∘22.9^\circ. A is wrong because AutoCAD never interprets a plain numeric entry in LENGTHEN Delta as degrees; that would require the Angle suboption. B confuses the formula by dividing by the diameter (1010) instead of the radius (55): 2/10=0.2 rad≈11.5∘2/10 = 0.2 \text{ rad} \approx 11.5^\circ, producing 71.5∘71.5^\circ — a classic off-by-two error on the radius/diameter distinction. D has no geometric basis; a positive delta shifts the endpoint by a fixed length, not a proportional multiplier. Your key study tip: always distinguish between LENGTHEN Delta's default (linear units) and its Angle suboption (degrees). Mixing them up is the most common trap on arc-editing questions.

Question 5

A horizontal line has endpoints at x=10x=10 and x=34x=34. The endpoint at x=34x=34 must remain fixed. The line must be shortened by 66 units using LENGTHEN.

After choosing Delta, entering −6-6, and selecting near the endpoint at x=10x=10, what is the resulting line?

  1. Its endpoints are x=4x=4 and x=34x=34, giving a length of 3030 units.
  2. Its endpoints are x=16x=16 and x=34x=34, giving a length of 1818 units. (correct answer)
  3. Its endpoints are x=10x=10 and x=28x=28, giving a length of 1818 units.
  4. Its endpoints are x=6x=6 and x=34x=34, giving a length of 2828 units.
Explanation: When using LENGTHEN with the Delta option, the key concept to understand is that AutoCAD modifies whichever end of the line you click near — it does not move the opposite endpoint. The delta value you enter is added (or subtracted) from that selected end. A negative delta shortens the line from the clicked end. Here, the original line runs from x=10x=10 to x=34x=34, giving a length of 2424 units. You enter −6-6 and click near the endpoint at x=10x=10. AutoCAD shortens the line from that end by 6 units, moving it inward (toward x=34x=34): 10+6=1610 + 6 = 16. The fixed end at x=34x=34 stays put. The result is a line from x=16x=16 to x=34x=34, with length 34−16=1834 - 16 = 18 units — confirming answer B. A is wrong because it places the new endpoint at x=4x=4, which would mean the line was extended outward (away from x=34x=34) by 6 units, not shortened inward. That would require a delta of +6+6 on that end, not −6-6. C is wrong because it moves the wrong endpoint — it shifts x=34x=34 to x=28x=28, as if you had clicked near the right end instead of the left. The endpoint you click is the one that changes. D is wrong because x=6x=6 reflects a −4-4 shift from x=10x=10, not −6-6 — likely a simple arithmetic error. The golden rule: whichever end you click, that's the end that moves. Always confirm which endpoint you're selecting before executing LENGTHEN.

Question 6

A line must keep one endpoint fixed and end at an existing point that lies on the line's current direction. The required final length has not been measured, but the target point can be acquired accurately with an object snap.

Which LENGTHEN workflow is the most efficient?

  1. Choose Percent, calculate what percentage of the current length reaches the target point, enter that value, and select the line near the movable endpoint.
  2. Choose Total, measure the distance to the target point first, enter that value, and select the line near the movable endpoint.
  3. Choose Delta, measure the distance from the current endpoint to the target point, enter that value, and select the line near the movable endpoint.
  4. Choose Dynamic, select the line near the movable endpoint, and drag it to the target point using an object snap. (correct answer)
Explanation: When a LENGTHEN question involves dragging to a known geometric point rather than a known numeric value, think about which option lets AutoCAD measure for you instead of making you measure first. The Dynamic option does exactly that. You activate it, click the line near the endpoint you want to move, and then drag that endpoint to any snappable point in the drawing — AutoCAD updates the length in real time. Because the target point is reachable with an object snap, you never need to calculate or measure anything; the geometry does the work. That's why D is the most efficient workflow here. The other options all force unnecessary manual measurement. A requires you to know both the current length and the target length so you can compute a percentage — two measurements plus arithmetic just to avoid one snap. B, the Total option, demands that you measure the final desired length and type it in; the scenario explicitly states that length hasn't been measured, so this is a dead end. C, Delta, asks for the change in length from the current endpoint to the target, which still requires you to measure a distance — a step the Dynamic mode eliminates entirely. All three of these workflows treat the problem as a numeric input task when it's actually a point-picking task. The exam strategy here: whenever a problem says the target location is geometrically defined (an existing point, intersection, endpoint, etc.) but no numeric length is given, Dynamic is almost always the right LENGTHEN choice because it lets object snaps replace manual calculation entirely.

Question 7

An arc of radius 88 units must have a final arc length of exactly 1212 units. The required endpoint may move along the existing circle, but the radius must not change.

Which use of LENGTHEN most directly satisfies the requirement?

  1. Choose Total, enter 1212, and select the arc near the endpoint that may move. (correct answer)
  2. Choose Delta, enter 1212, and select the arc near the endpoint that may move.
  3. Choose Total, choose Angle, enter 12∘12^\circ, and select the arc near the movable endpoint.
  4. Choose Percent, enter 12%12\%, and select the arc near the movable endpoint.
Explanation: When working with LENGTHEN in AutoCAD, the key is matching the option's behavior to the requirement's units. The question gives you a target in linear units (1212 units of arc length), so you need an option that accepts a direct length value — not a percentage, not an angle. The Total option sets the object's new total length to whatever value you enter. Since you want an arc length of exactly 1212 units, choosing Total, entering 1212, and selecting near the movable endpoint accomplishes this in one step. AutoCAD stretches or trims that endpoint until the arc measures 1212 units — radius unchanged, endpoint repositioned along the circle. That makes A the most direct solution. B is wrong because Delta adds or subtracts a value relative to the current length. If the arc is already, say, 1414 units long, entering 1212 would produce an 2626-unit arc, not a 1212-unit one. You'd need to calculate the difference first, which adds steps and room for error. C uses Total → Angle, which sets the arc's included angle to 12°12°. While an angle does indirectly define arc length (L=rθL = r\theta), the requirement is stated in linear units. This option forces you to convert, and 12°12° on an 88-unit radius gives approximately 1.681.68 units — nowhere near 1212. D uses Percent, which scales the arc to 12%12\% of its current length — again requiring you to know the current length and do extra math. The strategy to remember: when a question says "final length of exactly X units," always reach for Total in LENGTHEN. Reserve Delta for incremental changes and Percent for proportional scaling.

Question 8

A circular arc has an included angle of 75∘75^\circ. Its radius and center are correct, but the included angle must become exactly 135∘135^\circ by moving one endpoint.

Which LENGTHEN sequence sets the required final angle directly?

  1. Choose Delta, choose Angle, enter 135∘135^\circ, and select the endpoint to move.
  2. Choose Total, choose Angle, enter 135∘135^\circ, and select the endpoint to move. (correct answer)
  3. Choose Percent, enter 135%135\%, and select the endpoint to move.
  4. Choose Total, enter 135135 without the Angle suboption, and select the endpoint to move.
Explanation: When working with the LENGTHEN command on arcs, the key distinction is between how much to change versus what the final value should be. AutoCAD's LENGTHEN offers several modes, and choosing the right one depends on whether you're specifying a change or an absolute result. The Total option sets the arc's included angle to an exact final value — precisely what the problem demands. Since you want the arc to end at exactly 135∘135^\circ regardless of where it starts, you choose Total, then select the Angle suboption (because you're working with angular length, not linear length), enter 135135, and click the endpoint you want to move. AutoCAD recalculates and places that endpoint so the arc spans exactly 135∘135^\circ. That makes B the correct sequence. A is wrong because Delta adds or subtracts a change from the current value. To use Delta correctly here, you'd enter 60∘60^\circ (the difference between 135∘135^\circ and 75∘75^\circ), not 135∘135^\circ. Entering 135∘135^\circ in Delta mode would overshoot to 210∘210^\circ. C is wrong because Percent scales the arc relative to its current length — 135%135\% of 75∘75^\circ yields approximately 101.25∘101.25^\circ, not 135∘135^\circ. To reach 135∘135^\circ with Percent, you'd need 180%180\%. D is wrong because omitting the Angle suboption under Total causes AutoCAD to interpret your input as a linear length in drawing units, not an angular measure, producing an incorrect result. Study tip: On AutoCAD questions about LENGTHEN, always ask yourself two things: Is the value a final target (Total) or a change (Delta)? And is the measurement angular or linear? Both sub-decisions must match the problem.

Question 9

A line is currently 7.357.35 drawing units long. Its left endpoint is correctly located, and its right endpoint must be moved along the line's existing direction so that the final length is 9.109.10 units.

Which LENGTHEN workflow makes the required change without first calculating a new endpoint coordinate?

  1. Choose Delta, enter 1.751.75, and select the line near its right endpoint. (correct answer)
  2. Choose Delta, enter −1.75-1.75, and select the line near its right endpoint.
  3. Choose Total, enter 1.751.75, and select the line near its right endpoint.
  4. Choose Total, enter 9.109.10, and select the line near its left endpoint.
Explanation: When working with AutoCAD's LENGTHEN command, the key decision is choosing between Delta and Total mode, and understanding what value each one expects. Delta mode adds (or subtracts) an amount relative to the current length. Since the line needs to grow from 7.357.35 to 9.109.10 units, the required change is 9.10−7.35=1.759.10 - 7.35 = 1.75 units. Entering +1.75+1.75 in Delta mode and clicking near the right endpoint tells AutoCAD to extend that end by exactly 1.751.75 units along the existing direction — no coordinate math required. That's option A, which is correct. B is wrong because entering −1.75-1.75 in Delta mode shortens the line by 1.751.75 units, bringing it to 5.605.60 units — the opposite of what's needed. The negative sign reverses the direction of change. C is wrong because Total mode expects the final desired length, not the change amount. Entering 1.751.75 in Total mode would shrink the line to 1.751.75 units, not extend it to 9.109.10. D is wrong for two reasons: while entering 9.109.10 in Total mode is numerically correct, selecting the line near its left endpoint would move the left endpoint instead of the right one — violating the requirement that the left endpoint stay fixed. A quick memory aid: Delta = difference, Total = target. Also remember that LENGTHEN always moves the endpoint closest to where you click, so endpoint selection is just as important as the value you enter.

Question 10

Two collinear but separate line objects are 1818 units and 3131 units long. Their left endpoints are fixed. A drafter chooses LENGTHEN Total, enters 2525, and selects each line near its right endpoint.

Which statement correctly describes the result?

  1. Only the first line changes because Total cannot shorten an object already longer than the entry.
  2. Both lines gain 2525 units; their final lengths are 4343 and 5656 units.
  3. Both lines change by 77 units; their final lengths are 2525 and 3838 units.
  4. Both lines become 2525 units long; the first extends by 77 and the second shortens by 66. (correct answer)
Explanation: When you see a question involving LENGTHEN with the Total option, the key concept to hold onto is that Total sets an absolute final length — it is not an incremental change. Whatever value you enter becomes the new length of the selected object, regardless of whether that means extending or shortening it. Here, you enter 2525 as the total length and select each line near its right endpoint (which tells AutoCAD which end to move). The 1818-unit line is shorter than 2525, so AutoCAD extends its right end by 77 units, making it exactly 2525 units. The 3131-unit line is longer than 2525, so AutoCAD shortens its right end by 66 units, also making it exactly 2525 units. Both lines end up 2525 units long — confirming D is correct. A is wrong because it invents a restriction that doesn't exist. The LENGTHEN Total option absolutely can shorten an object; there is no minimum-length rule blocking it. B describes the LENGTHEN Delta behavior — adding a fixed increment — not Total. If you used Delta with 2525, the results would be 4343 and 5656, but that's the wrong command option entirely. C is another Delta-style trap: adding 77 to both lines implies an incremental operation, and the resulting lengths don't match what either option would actually produce. A reliable memory anchor: think of Total as "total makeover" — the number you type is the final length, full stop. Delta adds or subtracts; Total replaces.