Question

The length of the hypotenuse of a 30-60-90 triangle is 9. What is the perimeter?

Answer 1

The perimeter of any figure, is all its sides summed up

now, notice the picture below, using the 30-60-90 rule, that's "x"

now, get the other sides, since you know what "x" is, and sum them up, that's the perimeter

Answer 2

Hypotenuse = 9
Short leg = 9 / 2 = 4.5
Long leg = (4.5)(square root 3) = 7.8
9 + 4.5 + 7.8 = 21.3
PERIMETER = 21.3