Question

Solve for the missing variable.

Answer 1

There wasn't much to go off of but based of the information you've gave me the answer would be 7.68=6.28

Answer 2

Actually the circumference of a circle is :

C =2Pi*r

Where r = radius, the radius term r, was missing in your expression.

C = 2Pi*r

7.68 = 2*3.14*r

2*3.14*r = 7.68

6.28r = 7.68

r = 7.68 / 6.28

r ≈ 1.223

So in solving for the missing variable, r ≈ 1.223

Hope this explains it.