RD Sharma Solutions for Class 7 Chapter 20 “Mensuration- I” explain the concept of the area of few more plane figures and perimeters. Mensuration is the skill of measuring the length of lines, areas of surfaces, and volumes of solids from simple data of lines and angles. It is generally used where geometrical figures are concerned, where one has to determine various physical quantities such as perimeter, area, volume or length. Chapter 20 introduces students to the concept of Mensuration which can be defined as the mathematical branch that deals with the study of geometric shapes including their length, breadth, volume, area and other related concepts. With the help of Mensuration, one can quickly know about the different types of problems such as length, breadth and area of different types of geometric shapes such as square, triangle, rectangle and circle etc. These problems also have the day to day real-life applications such as measuring the height of a building or measuring how wide a bridge is. Maths constitutes topics related to units of measurement of area, perimeter and area of squares and rectangles, area between rectangles, area of a parallelogram and rhombus, area of a triangle via examples.