# RD SHARMA Solutions for Class 10 Mathematics Chapter 15: Areas related to circle

This chapter deals with the study of circles, their components, their measurements and calculations of their area. The distance covered by travelling once around a circle is its perimeter, also referred to as its circumference. The formula represents it:-

Circumference=2πr

where r is the radius of the circle.

The area of a circle can be calculated using the formula:-

Area= πr²

Chapter 15-Areas related to Circles also deals with the areas of the different components of a circle, namely, sector and segment. The definitions of sectors and segments are provided in Chapter 10-Circles. In this chapter, we shall study the calculation of areas of these components.

The area of a sector of a circle with angle, θ=θ/360×πr². Where r is the radius of the sector and θ is the angle of the sector.

Also, the length of the arc of a sector with angle, θ=θ/360×2πr.

Furthermore, Chapter 15- Areas related to circles also sheds light on the methods to calculate the area of some compound figures. This can be easily achieved by dividing the compound figure via straight lines into smaller figures comprising circles, triangles and rectangles.

An important formula that students must keep in mind in order to carry out the activity mentioned above is as follows:

Area of a segment of a circle = area of the corresponding sector – the area of the corresponding triangle.