##
**Important Formulas on Perimeter and Area**

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

2. Perimeter of a square = 4 × length of
a side.

3. Perimeter of a triangle = sum of all
its sides.

4. Perimeter of a parallelogram = 2 ×
(length + breadth).

5. Perimeter of a rhombus = 4 × length
of a side.

6. The total distance around a circle is
called its circumference.

7. The circumference of a circle of
radius r is 2Ï€r.

8. The ratio of the circumference of a
circle to its diameter is denoted using the notation ‘Ï€’.

9. The approximate value of Ï€ is 22/7 or
3.14.

10. Perimeter of a regular polygon =
(Number of sides of polygon) × (length of a side).

11. Area of a rectangle = length ×
breadth.

12. Area of a square = side × side.

13. Area of a triangle = 1/2 × base ×
height.

14. The area of a circle of radius r is
Ï€r

^{2}.
15. Area of a parallelogram = base × perpendicular
height.

16. Area of a rhombus = 1/2 × product of
its diagonals.

17. Area of a trapezium = 1/2 × sum of
parallel sides × height.

18. Area of a quadrilateral = 1/2 × (one
diagonal) × (sum of the perpendiculars to the diagonal from the opposite
vertices).

19. Area of a polygon = Sum of the areas
of various triangles and trapeziums into which the polygon is splitted.

20. The units of area are square units,
such as 1 cm

To see solved examples ----- Click Here!

^{2}= 100 mm^{2}; 1 m^{2}= 10,000 cm^{2}; 1 km^{2}= 10,00,000 m^{2}; 1 hectare = 10,000 m^{2 }; 1 acre = 4046.86 sq. m.To see solved examples ----- Click Here!