ACT Math › How to find the length of a line with distance formula
What is the distance between (1,5) and (6,17)?
Let and
So we use the distance formula
and evaluate it using the given points:
What is the distance of the line
Between and
?
Round to the nearest hundredth.
What is the distance of the line
Between and
?
To calculate this, you need to know the points for these two values. To find these, substitute in for the two values of given:
Likewise, do the same for :
Now, this means that you have two points:
and
The distance formulat between two points is:
For our data, this is:
This is:
or approximately
What is the distance between the x and y intercepts of:
Round to the nearest hundredth.
In order to find the distance between these two points, we first need the points! To find them, substitute in for x and y. Thus, for each you get:
Thus, the two points are:
and
The distance formulat between two points is:
For your data, this is very simply:
or
What is the area of a square with a diagonal that has endpoints at (4, **–**1) and (2, **–**5)?
5
10
20
25
100
First, we need to find the length of the diagonal. In order to do that, we will use the distance formula:
Now that we have the length of the diagonal, we can find the length of the side of a square. The diagonal of a square makes a 45/45/90 right triangle with the sides of the square, which we shall call s. Remember that all sides of a square are equal in length.
Because this is a 45/45/90, the length of the hypotenuse is equal to the length of the side multiplied by the square root of 2
The area of the square is equal to s2, which is 10.
What is the distance, in coordinate units, between the points and
in the standard
coordinate plane?
The distance formula is , where
= distance.
Plugging in our values, we get
In an _xy-_plane, what is the length of a line connecting points at (–2,–3) and (5,6)?
11.4
12.5
7.5
9.3
Use the distance formula:
D = √((_y_2 – _y_1)2 + (_x_2 – _x_1)2)
D = √((6 + 3)2 + (5 + 2)2)
D = √((9)2 + (7)2)
D = √(81 + 49)
D = √130
D = 11.4
Line segment has end points of
and
.
Line segemet has end points of
and
.
What is the distance between the midpoints?
The midpopint is found by taking the average of each coordinate:
and
The distance formula is given by
.
Making the appropriate substitutions we get a distance of 13.
Two towns—Town A and Town B—are represented by points on a map overlaid with a standard x- and y-coordinate plane. Town A and Town B are represented by points and
, respectively. If each unit on the map represents an actual distance of 20 miles, which of the following is closest to the actual distance, in miles, between these two towns?
13
64
169
260
261
In order to find the actual distance between these two towns, we must find the distance between these two points. We can find the distance between the points by using the distance formula, where the variable, , represents the distance:
The variables and
represent the x-values at each point and
and
represent the y-values at each point. We can calculate the distance by substituting the x- and y-coordinates of each point into the distance formula.
Since each unit on the map represents an actual distance of miles, the actual distance between the two cities can be calculated using the the following operation:
What is the distance between and
?
Let and
and use the distance formula:
. The distance formula is a specific application of the more general Pythagorean Theorem:
.