Question

Find the value of y.

8

16

8sqrt3

4sqrt3

Answer 1

ΔADC and ΔCDB are similar. Therefore the sides are in proportion:

`(DC)/(DA)=(DB)/(DC)`

Substitute:

`(y)/(4)=(12)/(y)` cross multiply

`(y)(y)=(4)(12)\\\\y^2=48\to y=√(48)\\\\y=√(16\cdot3)\\\\y=√(16)\cdot\sqrt3\\\\\boxed{y=4\sqrt3}`