Question

4.

If the difference between the circumference and
diameter of a circle is 30 cm, then what is the radius
of the circle?​

Answer 1

Answer:

circumference=2πr

diameter=2r

2πr-2r=30

2r(22/7-1)=30

r(22-7/7)=15

r(15/7)=15

r=15×7/15

r=7