If the radius of Circle A is 18, What is the EXACT Circumference?

Answer 1

radius = 18

circumference = 2pi(r) = 2pi(18) = 36pi

where pi= approximately 3.14159 or 22/7 but that's not exact

22/7 is a little larger than pi

3.14159 is slightly smaller than pi

pi is a decimal that never repeats and goes on forever. It's an irrational number which cannot be written as a/b where a and b are integers.

for radius 18, the circumference is 113.09724...... where ...... represents an endless series of decimals

Answer 2

Circumference = 2π r

r stands for radius

Therefore, the exact circumference of Circle A should be 2 x π x 18, which is 36π.