Hi Irene,
Is this what you mean by a triangular box?
If so then the volume is the box is the area of the triangle times the depth, d.
The area of the triangle you can find in two different ways. One is to choose a side of the triangle as the base and then the area is
triangle area = ^{1}/_{2} base height
An alternate way to calculate the area of a triangle is to use Heron's Formula.
Penny
