Question

find the diameter of a circle whose circumference is equal to the sum of circumferences of circles with radii 10 cm , 12cm , 18cm

Answer 1

so the diameter of circle be 80cm

Answer 2

Let d be the required diameter, then radius of the circle d/2

It is given that,

2π d/2 =2π(10)+2π(12)+2π(18)

⇒2π(d/2)=2π(10+12+18)

⇒ d/2 =40

⇒d=80cm.