CBSE NCERT Solutions for Class 8 Chapter 11

Chapter-wise, thorough solutions to the questions of the NCERT textbooks are provided with the aim of helping students compare their answers. Students are advised to practice the NCERT questions and solutions for class 8 on a regular basis to score well in their class 8 exam.

CBSE NCERT Solutions for Class 8 Maths Chapter 11:

Question-1:

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? [If required you can split the tiles in whatever way you want to fill up the corners]

Solution:

Given: Base of flooring tile = 24 cm
= 0.24 m
Corresponding height of a flooring tile
= 10 cm = 0.10 m
Now Area of flooring tile
= Base * Altitude
= 0.24 * 0.10
= 0.024 m2

Question-2:

Number of tiles required to cover the floor
= Area of floor / Area of one tile
= 1080 / 0.024
= 45000 tiles
Hence 45000 tiles are required to cover the floor.
The diagonals of a rhombus are 7.5 cm and 12 cm. Find its area.

Solution:

Given: d1 =7.5 cm and d2 = 12 cm
We know that,
Area of rhombus = ½ * d1* d2
= 1/2 *7.5 * 12
= 45 cm^2
Hence area of rhombus is 45 cm^2 .

Question-3:

The floor of a building consists of 3000 tiles which are rhombus shaped and each of its diagonals are 45 cm and 30 cm in length. Find the total cost of polishing the floor, if the cost per m^2 is ` 4.

Solution:

Here, d1 = 45 cm and d2= 30 cm
Area of one tile = 1/2 d1d2
= 1/2* 45* 30 = 675
Area of 3000 tiles
= 675 3000 = 2025000
=2025000/ 10000
= 202.50
Cost of polishing the floor per sq. meter = 4
Cost of polishing the floor per 202.50 sq. meter = 4 * 202.50 = 810
Hence the total cost of polishing the floor is 810.