Question

What is the value of x in the figure below?

15
C
D
B
X
20
A.
20
15
B. 10
C. 300
D. 5
E 20
OF
F.
45
4

Answer 1

choice f

Explanation:

take ∆ abc

ab^2 = ac^2 + ab^2

400 = 225 + ab^2

ab =√ 175

∆aDB

bd = 20-x

ad^2 = 175 -(20-x)^2

∆acd

225 = x^2 + 175 - 400+ 40x - x^2

225 = -225 + 40x

450 = 40x

x = 45/4