SOLUTION: what is the approximate srface area of a regular tetrahedron with edge length 12 cm?

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Question 144737: what is the approximate srface area of a regular tetrahedron with edge length 12 cm?
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A regular tetrahedron is composed of 4 triangular faces, here all sides are 12"
The area of a triangle is 1/2 of base times height, bh/2.
The height is sqrt%2812%5E2-6%5E2%29
h = sqrt%28108%29
The area of 1 triangle is 12sqrt%28108%29%2F2
The total is 4 times this, or 24sqrt%28108%29
Area = 249.415 square cm