Problem 2.1: If a circle's radius is 4, what is its circumference? [Solution]

Problem 2.2: If a circle's circumference is 24π, what is its radius? [Solution]

Problem 2.3: A 20 degree arc is what fraction of the circumference? [Solution]

Problem 2.4: What is the length of the major arc pictured below? (C is the center of the circle) [Solution]

Problem 2.5: A circle has a chord of length ten. What is the minimum circumference of the circle? [Solution]