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# A right triangle ABC with sides 5 cm, 12 cm and 13 cm is revolved about the side 12 cm. Find the volume of the solid so obtained.

**Solution:**

Since the triangle is revolved about the side 12 cm, a solid cone is formed with a height of 12 cm and radius of the base of 5 cm as shown below.

Volume of a cone having radius 'r', and height 'h', = 1/3πr²h

Radius of the cone, 'r' = 5 cm

Height of the cone, 'h' = 12 cm

Volume of the cone = 1/3πr²h

= 1/3 × π × 5 cm × 5 cm × 12 cm

= 100π cm³

Volume of the cone is 100π cm³.

**☛ Check: **NCERT Solutions for Class 9 Maths Chapter 13

**Video Solution:**

## A right triangle ABC with sides 5 cm, 12 cm and 13 cm is revolved about the side 12 cm. Find the volume of the solid so obtained.

NCERT Solutions for Class 9 Maths Chapter 13 Exercise 13.7 Question 7

**Summary:**

It is given that the right triangle ABC with sides 5 cm, 12 cm and 13 cm is revolved about the side 12 cm. We have found that the volume of the cone 100π cm³.

**☛ Related Questions:**

- The height of a cone is 15 cm. If its volume is 1570 cm3, find the radius of the base. (Use π = 3.14)
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- The volume of a right circular cone is 9856 cm³. If the diameter of the base is 28 cm, find i) height of the cone ii) slant height of the cone iii) curved surface area of the cone

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