Proof of the Formula[br][br]Let us assume that length of cube is [math]2l[/math] then the length of pyramid is [math]2l[/math]l and height of pyramid is [math]l[/math][br] Now,[br]  Volume of Cube = Volume of 6 pyramids[br] Base area x height = 6 x Volume of Pyramid[br]or volume of each pyramid=[math]\frac{1}{6}[/math] x Base area x [math]2l[/math] [br]or volume of each pyramid =[math]\frac{1}{3}[/math] x base area x [math]l[/math][br]or volume of each pyramid =[math]\frac{1}{3}[/math] x Base area x height of pyramid[br](Cube र pyramid को base area एउटै छ )[br]