Question

What is the length of PR

Answer 1

here is how i did it.

Answer 2

B 7

Explanation:

Since the triangles are similar by AAA

We can use ratios to find the length x (which is PR)

5 15

-------- = ------------

x 21

Using cross products

5 * 21 = 15 *x

Divide each side by 15

5/15 * 21 = 15x/15

1/3 * 21 =x

7 =x