What is the formula for volume of a triangle?

For those of us who live in a simple Euclidian world, a triangle is a two-dimensional shape, so it doesn't have volume, only area.

The formula for the area of a triangle is

V= 1/2 (bh) where b=base and h=height.

By the way, height must be measured perpendicular to the base.

Three Dimensional Forms

There are triangles that do indeed have a volume. For example, start at the north pole (pt 1); go due south along the prime meridian through London until you hit the equator (pt 2); then go due west along the equator until you are at the 90th merdian (pt 3); now go due north, passing near Madison, Wisconsin, until you return to the North Pole. Assuming the earth is a sphere (a pretty good approximation), you have traced out a spherical triangle with three right angles!

(see the related link about the spherical triangle)

To get the volume, integrate the product of dA*r from zero to the max radius, R and you will get a volume of 1/3*(A+B+C-pi)*R^3 where A,B and C are the three triangle angles, pi is 3.14159265... (all of these 4 quantities in radians, or unitless). In the example above, the right angle in radians is represented as pi/2.