ISEE Lower Level Math : How to find the perimeter of a rectangle

Study concepts, example questions & explanations for ISEE Lower Level Math

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Example Questions

Example Question #91 : Geometry

Dennis is building a fence around his field to keep his cattle from getting off the property. If Dennis’ field is  miles long and  miles wide, how much fence will Dennis need to surround all of his property?

Possible Answers:

Correct answer:

Explanation:

In order to determine how much fence Dennis will need, we must find the perimeter of his property, which can be found using the formula . When we plug  in the  and  in for , we find that Dennis needs  of fence to surround his property.

 

 

 

 

 

 

Example Question #92 : Geometry

Rectangle

Give the perimeter of the rectangle in the above diagram.

Possible Answers:

Correct answer:

Explanation:

Add the length and the height, then multiply the sum by two:

The rectangle has a perimeter of 58 inches.

Example Question #3 : How To Find The Perimeter Of A Rectangle

Rectangle

Give the perimeter of the above rectangle in feet.

Possible Answers:

Correct answer:

Explanation:

Use the following formula, substituting  :

Now, divide this by 12 to convert inches to feet.

6 inches make half of a foot, so this means the perimeter is  feet.

Example Question #2 : How To Find The Perimeter Of A Rectangle

What is the perimeter of a rectangle that has a length of  inches and a width of  inches? 

Possible Answers:

Correct answer:

Explanation:

The perimeter of a shape is the sum of all its sides. To find the perimeter of a rectangle, one can use the formula listed above, , since a rectangle has opposite sides of equal length.

The length of the rectangle is :

The width of the rectangle is :

.

Therefore, the perimeter is .  

Example Question #1 : How To Find The Perimeter Of A Rectangle

What is the perimeter of a rectangle with length equal to 5 and width equal to 3?

Possible Answers:

8

16

30

15

Correct answer:

16

Explanation:

Example Question #1 : How To Find The Perimeter Of A Rectangle

What is the perimeter of a rectangle with a width of  and a length of ?

Possible Answers:

Correct answer:

Explanation:

The perimeter of a rectangle is equal to the sum of all its sides. The formula for finding the perimeter of a rectangle is 

The length of the rectangle is eight, and the width is five; .

Therefore, the perimeter of the rectangle is .

Example Question #1 : How To Find The Perimeter Of A Rectangle

Mr. Barker is building a rectangular fence. His yard has an area of  feet, and the one side of the fence he's already built is  feet long. 

What will the perimeter of his fence be when he is finished building it?

Possible Answers:

Correct answer:

Explanation:

The perimeter is calculated by adding up all the sides of the rectangle—in this case,

So the perimeter is  feet.

Example Question #1 : How To Find The Perimeter Of A Rectangle

A rectangle has sides 10 cm and 4 cm. What is its perimeter?

Possible Answers:

Correct answer:

Explanation:

A rectangle has two sides of congruent, or equal, sides. Therefore, there are two 10 cm sides and two 4 cm sides. Perimeters is the sum of all the sides, so you must add up the four sides. The answer is 28 cm.

Example Question #71 : Rectangles

If a rectangle has a width of 6.5 inches and a length of 9 inches, what is its perimeter?

Possible Answers:

Correct answer:

Explanation:

The perimeter of a rectangle is found by adding together all four sides. Two sides will be equal to the length, and two sides will be equal to the width.

Since the width is 6.5 inches and the length is 9 inches, the perimeter would be:

Example Question #4 : How To Find The Perimeter Of A Rectangle

If Margaret is buying a tablecloth for a table that is 4 feet by 2 feet, what should be the area of the tablecloth?

Possible Answers:

Correct answer:

Explanation:

We will need to find the area of the rectangle by multiplying the length by the width:

Use the given dimensions:

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