### Home > PC > Chapter 4 > Lesson 4.3.1 > Problem 4-130

4-130.

A string around a circle is pulled up by a thumbtack,*T*, as shown below. The string is tangent to the circle with*AT*=*TB*. Given that the circle has a radius of*r*, complete the following problems. Homework Help ✎Find an expression for the length of the string if

*AT*=*r*.How long would the string have to be if

is 120°? Find

*m*∠*ATB*.

1.5π*r* + 2*r* ≈ 6.712*r*

60°