KSEEB Solutions for Class 8 Maths Chapter 11 Mensuration Ex 11.1

KSEEB Solutions for Class 8 Maths Chapter 11 Mensuration Ex 11.1

KSEEB Solutions for Class 8 Maths Chapter 11 Mensuration Ex 11.1

Question 1.
A square and a rectangular field with measurements as given in the figure have the same perimeter. Which field has a larger area?

Solution:
side of square = 60 m
length of rectangle = 80 cm
Perimeter of square = 4 × side
= 4 × 60
= 240 m
Perimeter of rectangle = 2 (l + b) = 2(80 + b)
Perimeter of rectangle = perimeter of square
⇒ 2(l + b) = 4 × side
⇒ 2(80 + b) = 4 × 60
⇒ 80 + b = 4×60/2
⇒ 80 + b = 120
⇒ b = 120 – 80
⇒ b = 40 m
Area of square = (side)²
= (60)²
= 60 × 60
= 3600 m²
Area of rectangle = l × b
= 80 × 40
= 3200 m²
The area of the square is larger than the area of a rectangle.

Question 2.
Mrs. Kaushik has a square plot with the measurement as shown in the figure. She wants to construct a house in the middle of the plot. A garden is developed around the house. Find the total cost of developing a garden around the house at the rate of 25 m Rs. 55 per m².

Area of garden = Area of plot – area of house
= 25 × 25 – 20 × 15
= 625 – 300
= 325 m²
Cost of developing the garden = 325 × 55 = Rs. 17875

Question 3.
The shape of a garden is rectangular in the middle and semicircular at the ends as shown in the diagram. Find the area and the perimeter of this garden [Length of rectangle is 20 – (3.5 + 3.5) meters].

Question 4.
A flooring tile has the shape of a parallelogram whose base is 24 cm and the corresponding height is 10 cm. How many such tiles are required to cover a floor of area 1080 m²? (If required you can split the tiles in whatever way you want to fill up the corners).
Solution:
Base of tile = 24 cm
Height of tile = 10 cm
Area of tile = 24 × 10 = 240 cm²