Question

Three circles, each with a radius of 10, are mutually tangent to each other. The area enclosed by the three circles can be written as ab√−cπ, where a, b and c are positive integers, and b is not divisible by a square of a prime. What is the value of a+b+c?

Answer 1

if c > 0, √−c is imaginary. You want to fix the problem?