What is the length of the entire string if we don't take into account the knotted part?

There is a circle-shaped mirror with a radius of 30 centimeters. After wrapping the mirror with string and hanging it on the wall, the angle formed by the string was 120 degrees. What is the length of the entire string if we don't take into account the knotted part?#sat #act #digitalsat#Trigonometric functions #digitalsat #math#sine#cosine#tangent