Question

The circumference of circle exceeds its diameter by 18 cm. Find the radus of circle

Answer 1

Hey mate..
________

Given,

The circumference of a circle exceed its diameter by 18 cm

So,

2πr = d + 18

=) πd = d + 18. ( °•° 2r = d )

=) πd - d = 18

=) d ( π - 1 ) = 18

=) d ( 22/7 - 1 ) = 18

=) d ( 22 - 7 / 7 ) = 18

=) d × 15 / 7 = 18

=) d = 18 × 7 / 15

=) d = 7 × 2

=) d = 14 cm

As,

d = r / 2

Thus, r = 7 cm

The required radius is 7cm

Hope it helps ✓✓

Answer 2

let the diameter of circle be 2r cm and radius be r cm
C= 2πr

it is given that the diameter is exceed by 18

2πr = d+18
πd = d+18
πd-d = 18
d(π-1) = 18
d(3.14-1)=18
d(2.14)=18
d=18/2.14
d=8.41cm
hence,
r=d/2
r=8.41/2
r=4.20cm

thanks for watching the answer.