Exercise 9 Page 392

Let's begin by plotting the points on a coordinate plane. Remember that the first value represents the x-coordinate and the second is the y-coordinate.

To determine if AB and CD are congruent, we should compare the length between A and B to the length between C and D. The length can be calculated by evaluating the absolute value of the difference between the x- or y-values, depending on if it's a horizontal or vertical line.

Let's start with calculating the length AB. Because it's a vertical line, we take the absolute value of the difference between the y-values of A and B.

AB=|y_A-y_B|

SubstituteII

y_A= 5, y_B= 8

AB = | 5- 8|

SubTerm

Subtract term

AB = |-3|

AbsNeg

|-3|=3

AB = 3

The length of AB is 3. Now we should compare it with the length of CD. It is also a vertical line, so we will calculate its length the same way as AB.

CD=|y_C-y_D|

SubstituteII

y_C= -3, y_D= 0

CD = | -3-( 0)|

SubTerm

Subtract term

CD = |-3|

AbsNeg

|-3|=3

CD= 3

If two segments have the same lengths, they are congruent segments. We can see that this is the case, both are equal 3. Therefore, they are congruent.