McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
Practice Test
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Exercise 7 Page 467

XZ=23

We are asked to find the measure of XZ which is expressed as 3x+5. To do so, we should first find the value of x. Let's consider the given diagram.

We can see that ∠ XWZ and ∠ YWZ have the same measure. Therefore, WZ is the bisector of ∠ XWY. From here, by the Angle Bisector Theorem, we can define the relationship between XZ and YZ.

Angle Bisector Theorem

If a point is on the bisector of an angle, then it is equidistant from the sides of the angle.

According to the theorem, Z is equidistant from the sides of ∠ XWY. In other words, XZ and YZ have the same length. With this information, we can set the expressions for their lengths equal to one another. 3x+5=5x-7 Let's solve this equation for x.
3x+5=5x-7
Solve for x
5=2x-7
12= 2x
6=x
x = 6
Now that we found the value of x, we will substitute x= 6 into the expression for XZ.
XZ=3x+5
XZ=3( 6)+5
XZ=18+5
XZ=23
The length of XZ is 23.