# Triangular Pyramid

*Go to Surface Area or Volume.*

Triangular Pyramid Facts

**Notice these interesting things:**

- It has 4 Faces
- The 3 Side Faces are Triangles
- The Base is also a Triangle
- It has 4 Vertices (corner points)
- It has 6 Edges
- It is also a Tetrahedron

images/polyhedra.js?mode=tetrahedron

## Surface Area

When side faces are the same:

**Surface Area** = [Base Area] + \frac{1}{2} × Perimeter × [Slant Length]

### Example: Base Area is 28, Perimeter is 20, Slant length is 5

Surface Area = [Base Area] + \frac{1}{2} × Perimeter × [Slant Length]

= 28 + \frac{1}{2} × 20 × 5

= 28 + 50

= 78

When side faces are different we can calculate the area of the base and each triangular face separately and then add them up.

## Volume

**Volume** = \frac{1}{3} × [Base Area] × Height

### Example: base area is 28, height is 4.5

Volume= \frac{1}{3} × [Base Area] × Height

= \frac{1}{3} × 28 × 4.5

= \frac{1}{3} × 126

= 42