If the radius of a circle is tripled, the area becomes
(a) 9 times
(b) 3 times
(c) 6 times
(d) 30 times

Solution:

Given, radius of a circle is tripled

We have to find the increase in area

Area of circle = πr²

Where, r is the radius of circle

Given, r = 3r

So, area = π(3r)²

= 9πr²

Therefore, the area of circle increases by 9 times

✦ Try This: If the radius of a circle is doubled, the area becomes

Given, radius of a circle is doubled

We have to find the increase in area

Area of circle = πr²

Where, r is the radius of circle

Given, r = 2r

So, area = π(2r)²

= 4πr²

Therefore, the area of circle increases by 4 times

☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 11

NCERT Exemplar Class 7 Maths Chapter 9 Problem 36

If the radius of a circle is tripled, the area becomes (a) 9 times, (b) 3 times, (c) 6 times, (d) 30 times

Summary:

If the radius of a circle is tripled, the area becomes 9 times.

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