### Home > INT2 > Chapter 12 > Lesson 12.1.3 > Problem 12-39

12-39.

For each of the diagrams below, write and solve an equation for the given variable. For parts (a) and (b), assume that *C* is the center of the circle. Show all work.

Radii of circles always have the same distance.

Remember that an inscribed angle measures half of a central angle.

The sum of a quadrilateral's interior angles is always

.