Question 144737
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(12^2-6^2)}}}
h = {{{sqrt(108)}}}
The area of 1 triangle is {{{12sqrt(108)/2}}}
The total is 4 times this, or {{{24sqrt(108)}}}
Area = 249.415 square cm