Question

How do you do this?

Answer 1

X/5 = 24/8
  (because the triangles are similar)

x/5 = 3

x = 5*3 = 15 Answer

a/27 = 8/24 = 1/3 
a =  9  Answer

Answer 2

3)a/8 = 27/24 => a = 8*27/24 = 9

x/24 = 5/8 => x = 24*5/8 = 15

4)C≡X, A≡Z, B≡Y

5)C=2πR=15π=>R=7,5

A = πR² = 56,25π cm²