Question

the circumstance of a circle is 40 cm more than diameter.calculate radius​

Answer 1

Answer:

let radius is r cm

diameter is 2r cm

circumference is 2πr cm

so,

2πr -2r=40

=> 2r(π-1)=40

=>r=40/2(π-1)=20/(22/7-1)

=> r=20/(22-7)/7

=> r=20×7/15=4×7/3=28/3

radius =28/3cm=9 1/3cm