Question 1.

If base of a parallelogram is 18 cm and its height is 11 cm, find its area.

Solution:

Given, base = 18 cm, height = 11 cm

Area of a parallelogram = base × height

= 18 × 11

= 198 sq.cm

∴ Area of the parallelogram is 198 sq.cm.

Question 2.

If area of a parallelogram is 29.6 sq. cm and its base is 8 cm, find its height.

Solution:

Given, area of a parallelogram = 29.6 sq.cm,

base = 8 cm

Area of a parallelogram = base × height

∴ 29.6 = 8 × height

∴ height = 29.6/8= 3.7 cm

∴ Height of the parallelogram is 3.7 cm.

Question 3.

Area of a parallelogram is 83.2 sq.cm. If its height is 6.4 cm, find the length of its base.

Solution:

Given, area of a parallelogram = 83.2 sq.cm, height = 6.4 cm

Area of a parallelogram = base × height

∴ 83.2 = base × 6.4

∴ base = 83.2/6.4 = 13 cm

∴ The length of the base of the parallelogram is 13 cm.

**Intext Questions and Activities**

Question 1.

Draw a big enough parallelogram ABCD on a paper as shown in the figure.

Draw perpendicular AE on side BC.

Cut the right angled ∆AEB. Join it with the remaining part of ₹ABCD as shown in the figure.

The new figure formed is a rectangle.

The rectangle is formed from the parallelogram.

So, areas of both the figures are equal.

Base of parallelogram is one side (length) of the rectangle and its height is the other side (breadth) of the rectangle.

∴ Area of a parallelogram = base × height (Textbook pg. no.94)

Solution:

Draw a big enough parallelogram ABCD on a paper as shown in the figure.

Draw perpendicular AE on side BC.

Cut the right angled ∆AEB. Join it with the remaining part of ₹ABCD as shown in the figure.

The new figure formed is a rectangle.

The rectangle is formed from the parallelogram.

So, areas of both the figures are equal.

Base of parallelogram is one side (length) of the rectangle and its height is the other side (breadth) of the rectangle.

∴ Area of a parallelogram = Area of a rectangle = length × breadth = base × height