Learn Class 7 Math - Perimeter and Area

The term perimeter refers to the coverage of the length of a figure from the outside. At the same time, the area is known as the object's surface. For different sets of figures, there are different formulas.

Different figures

Here, all different figures consist of different perimeters and areas. These are:

• Square

  The perimeter of the square is 4a, and its area is a^2.

  Note: In the formula, a is the side of a square.

• Rectangle

  The rectangle's perimeter is 2 (l + b), and its area equals l x b.

  Note: In the formula, l & b are the length and breadth of the square.

• Circle

  The circle's perimeter is 2πr, and its area is equal to πr^2.

  Note: r is the radius of a circle, i.e., r = 2d (d = diameter)

• Triangle

  The triangle's area is equal to ½ x b x h.

• Parallelogram

  The parallelogram's area is b x h.

Units Conversion

To get the area and perimeter of a closed figure, we have to consider all figures in one unit. Only then do we have to apply the formula to get the results.

• 1 cm = 10 mm
• 1 m = 100 cm
• 1 km = 1000 m
• 1 hectare = 100 x 100 m