If the area of a circle is 154 cm², then its perimeter is
a. 11 cm
b. 22 cm
c. 44 cm
d. 55 cm

Solution:

Given, area of a circle is 154 cm²

We have to find the perimeter of the circle.

Area of a circle = πr²

Where r is the radius of the circle.

So, 154 = πr²

Use π = 22/7

154 = (22/7)r²

r² = 154(7)/22

r² = 7(7)

So, r = 7 cm

Perimeter of the circle = circumference

Circumference of the circle = 2πr

= 2(22/7) (7)

= 2(22)

= 44 cm

Therefore, the circumference of the circle is 44 cm.

✦ Try this: If the area of a circle is 110 cm², find the radius of the circle.

Given, area of the circle is 110 cm²

We have to find the radius of the circle.

Area of a circle = πr²

Where r is the radius of the circle.

So, 110 = πr²

Use π = 22/7

110 = (22/7)r²

r² = 110(7)/22

r² = 5(7)

r² = 35

Taking square root,

r = √35

r = 5.916 cm

Therefore, the radius of the circle is 5.916 cm.

☛ Also Check: NCERT Solutions for Class 10 Maths Chapter 12

NCERT Exemplar Class 10 Maths Exercise 11.1 Sample Problem 1

If the area of a circle is 154 cm², then its perimeter is a. 11 cm, b. 22 cm, c. 44 cm, d. 55 cm

Summary:

A circle is a two-dimensional figure formed by a set of points that are at a constant or at a fixed distance (radius) from a fixed point (center) in the plane. If the area of a circle is 154 cm², then its perimeter is 44 cm

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