A regular tetrahedron is a four sided pyramid with each side being an equilateral triangle. Let x be the length of the triangle's side.

Question

a) Prove that the surface area of a tetrahedron is V=x(cubed)(root)2/12

b) Prove that the surface area of a tetrahedron is SA=x(squared)(root)3

c) How fast is the surface area of a tetrahedron growing if the volume is growing at 10 cm(cubed)/second, when the volume is 118 cm(cubed)?