SOLUTION: Find the area of an equilateral triangle with height of 9 inches.

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Question 277768: Find the area of an equilateral triangle with height of 9 inches.

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
if the height is 9 then the base equals s/2
9/sqrt(3)=9sqrt(3)/3=3 sqrt(3)
A=1/2 bh
we have a 30 60 90 triangle
x=3 sqrt(3)
2x=6 sqrt(3)
sqrt(3)*x=9
b=3/2sqrt(3)
h=9
1/2 bh=1/2*9*3/2*sqrt(3)=27/4sqrt(3)
6.25sqrt(3)