Question

What is the value of x?

Answer 1

X/16 = 9 /x
x^2 = 9*16
x^2 = 144
    x = 12

Answer 2

The three right triangles are similar, so the length of corresponding sides are in he same ratio.

9/x = x/16

x^2 = 9 * 16

x^2 = 144

x = 12