Question

the area of a circle is 154cm square. find its circumference

Answer 1

area=154cm square
area=pi r square
154cm=22/7×r ×r
154cm×7/22=r×r
49cm=r square
r=7cm

circumference =2 pi r
2×22/7×7cm
2×22cm
44cm

Answer 2

Given:

The area of the circle = 154 cm²

To find:

The circumference of the circle

Calculation:

Let ‘r’ be the radius of the circle

Area of the circle = πr²

=>  πr² = 154

     (22/7)r² =  154

     r² = 49

     r = 7 cm

   

=> Circumference of the circle = 2πr

                                              = 2×(22/7)×7

                                              = 44 cm

The circumference of the circle is 44 cm