SOLUTION: What is the area of an equilateral triangle that has an altitude of 9?
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Question 576246: What is the area of an equilateral triangle that has an altitude of 9?
Answer by nerdybill(7384) (Show Source): You can put this solution on YOUR website!
What is the area of an equilateral triangle that has an altitude of 9?
An equilateral triangle tells us that all three sides are equal.
Area = (1/2)bh
first, we need to find the length of the base
Let b = length of base
then from Pythagorean theorem we have
(b/2)^2 + 9^2 = b^2
b^2/4 + 81 = b^2
81 = b^2 - b^2/4
81 = b^2(1 - 1/4)
81 = b^2(3/4)
81(4/3) = b^2
81(4/3) = b^2
108 = b^2
10.39 = b
.
Area = (1/2)bh
Area = (1/2)(10.39)(9)
Area = 46.77
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