The type for the circumference of the circle is : L( circumference)= 2πr so you have to do 2π4 that equals to 25,13 ;)

The type for the circumference of the circle is : L( circumference)= 2πr so you have to do 2π4 that equals to 25,13 ;)

Generally, when you say a   1 inch hole it means the diameter, so I assume a 4 cm circle refers to the DIAMETER of the circle ...CIRCUMFERENCE is pi x d

pi x 4 = 12.56 cm circumference