Have you seen a real pyramid in life? Think of great pyramids of Egypt once and you will recall the concepts yourself. A pyramid is a three-dimensional shape here with

Here, the triangular sides are named as faces and the bottom polygon is recalled as base of the pyramid. The number of sides for a pyramid would be equal to the total number of sides or triangular faces of a pyramid. The common point where all triangular faces meet is called the Apex.

A pyramid could be any polygon as a base, hence the structure of base is not fixed here. Let us take an example where base is triangular. Since we know that a triangle has three sides then the triangular pyramid would have three triangular bases in that case. They are common in other areas too like architecture, art, designing or more.

\[\ Volume\;of\;a\;triangular\;pyramid=\frac{1}{3}Base\;Area\times Height\]

\[\ Surface\;area=Base\;Area+\frac{1}{2}Perimeter\times Side\;length\]

Now there are two more possible cases for the triangular pyramid. These are regular pyramid and non-regular pyramid. A regular pyramid has a base whose all three sides are equal in length and for a non-regular pyramid; the base has sides of different lengths. Further, you could calculate the volume or surface area for a triangular pyramid too. You have to use the triangular pyramid formula as given in mathematics. Volume for a pyramid could be defined as the total space occupied by the pyramid. And the surface area could be given as total area of all its faces and base combined.

**Question 1: **Find the volume of a triangular pyramid when base area is 9 cm^{2} and height is 4 cm ?

**Solution:
**Given,

Base area = 9 cm