### Mensuration - Revision Notes

CBSE Class 6 Mathematics

Revision Notes

CHAPTER – 10

Mensuration

- Perimeter is the distance covered along the boundary forming a closed figure when you go round the figure once.

(a) Perimeter of a rectangle = 2 × (length + breadth)

(b) Perimeter of a square = 4 × length of its side

(c) Perimeter of an equilateral triangle = 3 × length of a side

(d) Perimeter of a regular pentagon has five equal sides = 5 × length of a sides - Figures in which all sides and angles are equal are called regular closed figures.
- The amount of surface enclosed by a closed figure is called its area.
- To calculate the area of a figure using a squared paper, the following conventions are adopted :

(a) Ignore portions of the area that are less than half a square.

(b) If more than half a square is in a region. Count it as one square

(c) If exactly half the square is counted, take its area as sq units. - Area of a rectangle = length × breadth
- Area of a square = side × side