Answer:
6 sqrt(3) = y
Explanation:
We can use the leg rule to find y
hyp leg
----- = -------
leg part
9+3 y
----- = -------
y 9
Using cross products
12*9 = y^2
108 = y^2
Taking the square root of each side
sqrt(108) = sqrt(y^2)
sqrt(36 *3) = y
6 sqrt(3) = y