### Home > MC2 > Chapter 7 > Lesson 7.1.4 > Problem7-40

7-40.

Find the missing measure(s) of each circle.

Remember:
Circumference $= 2 · π · r$
Diameter $= 2 · r$
Use these given formulas to solve for the missing information by substituting in given measurements and solving.

1. diameter $=$ ?
circumference $=$ ?

Circumference $= 24π = 78.4$ cm

1. diameter $=$ ?
radius $=$ ?

Radius $=30$ cm