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# Solution - The Radii of the Circular Bases of a Frustum of a Right Circular Cone Are 12 Cm and 3 Cm and the Height is 12 Cm. Find the Total Surface Area and the Volume of the Frustum. - CBSE Class 10 - Mathematics

ConceptSurface Area of a Combination of Solids

#### Question

The radii of the circular bases of a frustum of a right circular cone are 12 cm and 3 cm and the height is 12 cm. Find the total surface area and the volume of the frustum.

#### Solution

The height of the frustum cone is h= 12 cm. The radii of the bottom and top circles are r1 = 12cm and r2 = 3cm respectively.

The slant height of the frustum cone is

l=sqrt((r_1-r_2)^2+h^2

=sqrt((12-3)^2+12^2

=sqrt(225)

= 15 cm

The total surface area of the frustum cone is

=pi(r_1+r_2)xxl+pir_2^2+pir_2^2

=pixx(12+3)xx15+pixx12^2+pixx3^2

= π x 225 x 26 + 144π + 9π

= 378π cm2

Hence Total surface area = 378π cm2

The volume of the frustum cone is

V=1/3pi(r_1^2+r_1r_2+r_2^2)xxh

=1/3pi(12^2+12xx3+3^2)xx12

=1/3xxpixx189xx12

= 756π cm3

Hence Volume of frustum = 756π cm3

Is there an error in this question or solution?

#### APPEARS IN

R.D. Sharma 10 Mathematics (with solutions)
Chapter 16: Surface Areas and Volumes
Q: 8

#### Reference Material

Solution for question: The Radii of the Circular Bases of a Frustum of a Right Circular Cone Are 12 Cm and 3 Cm and the Height is 12 Cm. Find the Total Surface Area and the Volume of the Frustum. concept: Surface Area of a Combination of Solids. For the course CBSE
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