Mensuration is a branch of mathematics that deals with measuring geometric figures. It is concerned with the calculation of the areas, perimeters, volumes, and surface areas of different 2D and 3D shapes.

The two main types of measurement are:

**2D mensuration** deals with the measurement of 2D shapes, such as squares, rectangles, triangles, circles, and ellipses.
**3D mensuration** deals with the measurement of 3D shapes, such as cubes, cuboids, spheres, pyramids, and cones.

Some of the common formulas used in measurement are:

- Area of a square = side²
- Area of a rectangle = length × breadth
- Area of a triangle = 1/2 × base × height
- Area of a circle = πr²
- Perimeter of a square = 4 × side
- Perimeter of a rectangle = 2 × (length + breadth)
- Perimeter of a triangle = sum of all sides
- Volume of a cube = side³
- Volume of a cuboid = length × breadth × height
- Volume of a sphere = 4/3 πr³
- Volume of a pyramid = 1/3 × area of base × height
- Volume of a cone = 1/3 πr²h

Some of the basic concepts of mensuration include:

**Area** is the amount of space enclosed by a 2D shape.
**Perimeter** is the total length of all the sides of a 2D shape.
**Volume** is the amount of space enclosed by a 3D shape.
**Lateral surface area** is the area of the faces that are not the base or the top of a 3D shape.
**Total surface area** is the sum of the areas of all the faces of a 3D shape.

Mensuration is an important branch of mathematics that is used in many different fields, such as engineering, architecture, and construction. It is also used in everyday life, such as when we need to calculate the amount of paint needed to cover a wall or the amount of material needed to build a fence.