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

Learning Videos for 7th Grade Math - Perimeter and Area

Perimeter and Area Sample Questions for Class 7

Question 1

What is this measurement called?
A. Area
B. Circumference
C. Diameter
D. Radius

Question 2

What is the area of a triangle with height 8 inches and base 2 inches?
A. 8 square inches
B. 2 square inches
C. 16 square inches
D. 6 square inches

Question 3

The perimeter of a regular hexagon is 48. If the side length of a similar hexagon is 3 times that of the original hexagon, which statement is true about the similar hexagon?
A. The perimeter of the similar hexagon is 3 times the perimeter of the original hexagon.
B. The perimeter of the similar hexagon is 8 times the perimeter of the original hexagon.
C. The perimeter of the similar hexagon is 11 times the perimeter of the original hexagon.
D. The perimeter of the similar hexagon is 24 times the perimeter of the original hexagon.

Question 4

The area of the circle is 64pi. Which expression should be used to find the area of the shaded regions?
A. 64 - 8pi
B. 8pi - 64
C. 256-64pi
D. 64pi-256

Question 5

A triangle has an area of 49.5 \ "cm"^2. If the base of the triangle is 9 cm, what is the height of the triangle?Use A=(1/2)bh.
A. 5.5 cm
B. 11 cm
C. 222.75 cm
D. 445.5 cm