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Chapter 11 Perimeter and Area Exercise 11.2


Question 1.
Find the area of each of the following parallelograms:

NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 1
Solution:
(a) Area of the parallelogram
= base × altitude = 7 cm × 4 cm
= 28 cm2
(b) Area of the parallelogram
= base × altitude = 5 cm × 3 cm
= 15 cm2
(c) Area of the parallelogram
= base × altitude = 2.5 cm × 3.5 cm
= 8.75 cm2
(d) Area of the parallelogram
= base × altitude = 5 cm × 4.8 cm
= 24.0 cm2
(e) Area of the parallelogram
= base × altitude = 2 cm × 4.4 cm
= 8.8 cm2

Question 2.
Find the area of each of the following triangles:
NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 2


Question 3.
Find the missing values:

S.No.

Base

Height

Area of the parallelogram

(a)

20 cm

246 cm2

(6)

15 cm

154.5 cm2

(c)

8.4 cm

48.72 cm2

(d)

15.6

16.38 cm2

Solution:
(a) Area of the parallelogram =b × h
246 = 20 × h
NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 4

(b) Area of the parallelogram = b × h
154.5 = b × 15

(c) Area of the parallelogram = b × h
48.72 = b × 8.4
NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 6

(d) Area of the parallelogram = b × h
16.38 = 15.6 × h

Question 4.
Find the missing values:

Base

Height

Area of the triangle

15 cm

87 cm2

31.4 mm

1256 mm2

22 cm

170.5 cm2

Question 5.
PQRS is a parallelogram. QM is the height of Q to SR and QN is the height from Q to PS. If SR = 12 cm and QM = 7.6 cm. Find:
(a) the area of the parallelogram PQRS
(b) QN, if PS = 8 cm


Solution:
(a) Area of the parallelogram PQRS
= SR × QM (∵ Area = Base × Height)
= 12 cm × 7.6 cm
= 91.2 cm2

(b) Area of the parallelogram PQRS

Question 7.
∆ABC is right angled at A. AD is perpendicular to BC. If AB = 5 cm, BC = 13 cm and AC = 12 cm, find the area of ∆ABC. Also find the length of AD.


Solution:
Area of right triangle ABC

NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 A1
NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 A2
NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 A3
NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 A4
NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 A5
NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 A6
NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.2 A7

Chapter 11 Perimeter and Area Exercise 11.2