If we rotate a right-angled triangle of height 5 cm and base 3 cm about its base, we get:
(a) cone of height 3 cm and base 3 cm
(b) cone of height 5 cm and base 5 cm
(c) cone of height 5 cm and base 3 cm
(d) cone of height 3 cm and base 5 cm

Solution:

We know that

The definition for a right triangle states that if one of the angles of a triangle is a right angle - 90º, the triangle is called a right-angled triangle or simply, a right triangle.

Here if we rotate a right-angled triangle of height 5 cm and base 3 cm about its base, we get a cone of height 3 cm and base 5 cm.

Therefore, we get a cone of height 3 cm and base 5 cm.

✦ Try This: If we rotate a right-angled triangle of height 7 cm and base 5 cm about its base, we get:

(a) cone of height 5 cm and base 5 cm

(b) cone of height 7 cm and base 7 cm

(c) cone of height 7 cm and base 5 cm

(d) cone of height 5 cm and base 7 cm

We know that

The definition for a right triangle states that if one of the angles of a triangle is a right angle - 90º, the triangle is called a right-angled triangle or simply, a right triangle.

Here if we rotate a right-angled triangle of height 7 cm and base 5 cm about its base, we get a cone of height 5 cm and base 7 cm.

Therefore, we get a cone of height 5 cm and base 7 cm.

☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 10

NCERT Exemplar Class 7 Maths Chapter 12 Problem 18

If we rotate a right-angled triangle of height 5 cm and base 3 cm about its base, we get: (a) cone of height 3 cm and base 3 cm, (b) cone of height 5 cm and base 5 cm, (c) cone of height 5 cm and base 3 cm, (d) cone of height 3 cm and base 5 cm

Summary:

If we rotate a right-angled triangle of height 5 cm and base 3 cm about its base, we get a cone of height 3 cm and base 5 cm.

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