Question

The sum of the circumference and the diameter of a circle 87 cm. Find radius. ​

Answer 1

Depending on format: 10.51 cm or 87/2π+2 cm

Explanation:

C= Circumference

d= diameter

r=radius

π=3.14 (or however you interpret pi)

Given:

C+d=87

We know that the formula for...

>...Circumference is:

C=2πr

>...diameter is

d=2r

Substitute

2πr + 2r = 87

Then you factor out r

r(2π+2)=87

Divide (2π+2) on both sides to isolate the r

r(2π+2)/(2π+2)=87/(2π+2)

r=87/(2π+2)

r= 10.51 cm