Question

What is the value of a?
✅6√2
❌9
❌8√3
❌36√2

Answer 1

6√2.

Explanation:

Triangles CDE and DBE are similar.

Therefore:

a / 18 = 4 / a

a^2 = 4*18

a^2 = 72

a^2 = 36*2

a = √36*√2

a = 6√2.