Solve for y A. 8 B. 3 √(7) C. 4 √(7) D. 12

Question

Solve for y

A. 8

B.

`3 √(7)`
C.

`4 √(7)`
D. 12

Answer 1

Triangle ADC and triangle BCD are similar, therefore the sides are in proportion:

`(y)/(9)=(7)/(y)`

cross multiply

`y^2=9\cdot7\to y=√(9\cdot7)\\\\y=\sqrt9\cdot\sqrt7\\\\y=3\sqrt7`

Answer: B. 3√7