NCERT Solutions for Class 7 Maths Chapter 11 Perimeter and Area Ex 11.4

Class 7 Maths NCERT Solutions Chapter 11 Perimeter and Area Ex 11.4

Question 1.
A garden is 90 m long and 75 m broad. A path 5 m wide is to be built outside and around it. Find the area of the path. Also, find the area of the garden in a hectare.
Solution:

Question 2.
A 3 m wide path runs outside and around a rectangular-park of length 125 m and the breadth 65 m. Find the area of the path.
Solution:

Question 3.
A picture is painted on a cardboard 8 cm long and 5 cm wide such that there is a margin of 1.5 cm along each of its sides. Find the total area of the margin.
Solution:

Question 4.
A verandah of width 2.25 m is constructed all along outside a room which is 5.5 m long and 4 m wide. Find :
(i) the area of the verandah,
(ii) the cost of cementing the floor of the verandah at the rate of ₹ 200 per m².
Solution:

Question 5.
A path 1 m wide is built along the border inside a square garden of side 30 m. Find :
(i) the area of the path,
(ii) the cost of planting grass in the remaining portion of the garden at the rate of ₹ 40 per m².
Solution:

Question 6.
Two crossroads, each of width 10 m, cut at right angles through the center of a rectangular park of length 700 m and breadth 300 m and parallel to its sides. Find the area of the roads. Also, find the area of the park excluding crossroads. Give the answer in hectares.
Solution:

Question 7.
Through a rectangular field of length 90 m and breadth 60 m, two roads are constructed which are parallel to the sides and cut each other at right angles through the center of the fields. If the width of each road is 3 m, find :
(i) the area covered by the roads,
(ii) the cost of constructing the roads at the rate of ₹ 110 per m².
Solution:

Question 8.
Pragya wrapped a cord around a circular pipe of a radius of 4 cm (adjoining figure) and cut off the length required of the cord. Then she wrapped it around a square box of side 4 cm (also shown). Did she have any cord left? (π = 3.14)

Solution:

Question 9.
The adjoining figure represents a rectangular lawn with a circular flower bed in the middle. Find :
(i) the area of the Whole land,
(ii) the area of the flower bed,
(iii) the area of the lawn excluding the area of the flower bed,
(iv) the circumference of the flower bed.

Solution:

Question 10.
In the following figures, find the area of the shaded portions :

Solution:

Question 11.
Find the area of the quadrilateral ABCD.
Here, AC = 22 cm,
BM = 3 cm,
DN = 3 cm, and BM ⊥ AC, DN ⊥ AC.

Solution: