It is a very important chapter for students because many new topics are introduced, like the area of trapezium, area of polygon, area of general quadrilaterals and special quadrilaterals. In this, we also learn about volume and surface area of solids such as cylinder, cube, and cuboid. The NCERT Solutions for Class 8 Maths Chapter 11 Mensuration are prepared and explained by the experts. Mathematics requires a lot of practice and concentration.
What is Mensuration?
Mensuration is a branch of mathematics in which we deal with different geometric shapes both 2D and 3D shapes. A 2D shape is bounded by a closed circular line or three or more straight lines in a plane like a circle, quadrilateral, triangle etc. These shapes have no height or depth; 2D shapes can be measured by two dimensions- length and breadth. For 2-Dimensional shapes, we measure the area (A) and perimeter(P). A 3D shape is bounded by a number of planes or surfaces. These shapes can be measured by three dimensions-length, width, and depth/height. For 3 Dimensional shapes we measure Curved Surface Area (CSA), Total Surface Area (TSA), Lateral Surface Area (LSA) and Volume (V).In NCERT Class 8 Maths Chapter 11 Mensuration we deal with problems based on both 2D and 3D shapes.
Before going in detail of Class 8 Maths Chapter 11 Mensuration we need to discuss some important terms like perimeter and area. Let’s understand with some scenarios that we come across in our daily life, we have a field and we want to fence the field it means we want to put the boundary on that field. So, how much raw material we need to fence the field. So, in order to know that we need to find out the entire length of the boundary.
Let’s take another example- we want to laminate the door. In order to laminate, we should know what is the total area of the door so we can arrange for materials to get it laminated.
The concept behind in these two examples is when we are talking about the length of the boundary it means we are talking about perimeter and when we are talking about the entire space that time we are talking about the area. That is something we will focus on in this chapter. There are NCERT Class 8 Maths Chapter 11 Mensuration 4 exercises with 34 questions.
Example: A box in the shape of a cube has a side length of 10 cm
i) How many faces are there
ii) calculate the perimeter of a single phase
iii) calculate the perimeter of the whole cube? Is it equal to the number of faces perimeter of a single phase? If not why?
iv) Find the area of a side?
v) find the area of the whole cube? Is it equal to the number of faces area of a side? Justify your answer
NCERT Solutions to the following exercises of Class 8 Maths Mensuration;
|Chapter -1||Rational Numbers|