## RD Sharma Class 9 Solutions Chapter 20 - Surface Area and Volume of Right Circular Cone (Ex 20.2) Exercise 20.2 - Free PDF

## FAQs on RD Sharma Class 9 Solutions Chapter 20 - Exercise 20.2

**1. How will RD Sharma Class 9 solutions for Chapter 20 - Surface Area and Volume of Right Circular Cone help with the exam preparation?**

RD Sharma Class 9 Solutions Chapter 20 - Surface Area and Volume of Right Circular Cone Can you help you in the following mentioned ways-

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**2. Describe the significance of Class 9 Chapter 20- Surface Area and Volume of Right Circular Cone.**

Chapter 20 - Surface Area And Volume of the Right Circular Cones has much significance. Listed below are a few:

The Area and Volume of Right Circular Cones- For a right circular cone with radius 'r', height 'h', and slant height 'l', we have: Curved surface area of right circular cone = πrl. Right circular cones have a surface area of π(r + l) r. A right circular cone has a volume of 1/3πr

^{2}hYou can calculate the formula even with diagrams if you mark the ends of each cone and mention each side of it.

**3. Following the concepts of RD Sharma Class 9 Chapter 20 Maths, solve the given question:**

### Assume a cone has a height and slant height of 21 cm and 28 cm respectively. Determine the volume.

The height of the cone i.e. the total height (h) = 21 cm

The slant height of the cone (l) is 28 cm

Calculate the radius of the cone:

We know that l^{2} = r^{2} + h^{2}

282 = r^{2} + 212

or r = 7√7 cm

As a result,

We know that volume of a cone = 1/3 * r^{2}h

= 1/3 x π x (7√7 )2 x 21

= 2401 π

Thus, the cone has a volume of 2401 π cm^{3}.

**4. Following the concepts of RD Sharma Class 9 Chapter 20 Maths, is the surface area of a right circle equal to its total surface area?**

Total surface area is essentially the total area underneath a sphere is defined as the total area or region under the sphere, including the area under the circular base. The top and bottom of a cylinder are two congruent circles that are known as bases. The height of a cylinder is equal to the distance between its circular bases, while its radius equals the distance between its circular bases. e calculated using the formula, Total surface area of a cone = πr^{2} + πrs, where, 'r' is the radius, 's' is the slant height, and 'h' is the height of the cone.

**5. Following the concepts of RD Sharma Class 9 Chapter 20 Maths, what is the difference between height and slant height?**

The "height" of a cone and the "slant height" of a cone are two different things. Height or the altitude of a cone is referred to as its vertical height, ie. Ax^{2} + Bx^{2} = Cx^{2} can be used to calculate the slant height. In this formula, a represents the altitude, b represents the angle between the centre of the base and the starting point of the slant height segment, and c represents the slant height. This is the distance perpendicular to the cone's top from the base of the cone to the top. A cone's slant height is the height at which the side of the cone meets the edge of its circular base.