Answer:
x=5/2
Step-by-step explanation:
We can use ratios of similar triangles to help solve the problem.
side x 5
-------- = --------------- = ---------------
hypotenuse 4 8
Using cross products
x*8 = 4 * 5
8x = 20
Divide each side by 8
8x/8 = 20/8
x = 5/2
