Area, Circumference, and Sectors

What is the exact area of this circle?

Recall: $A=\pi r^2$  and  $C=2\pi r$  

A Circle has a radius of 4. What is the circumference of the circle? 
Recall:   $A=\pi r^2$  and  $C=2\pi r$  

A Circle has a radius of 4. What is the area of the circle?  Recall:   $A=\pi r^2$  and  $C=2\pi r$  

A Circle has a radius of 6 inches. What is the circumference of the circle?
Recall: $A=\pi r^2$  and  $C=2\pi r$  

 A Circle has a radius of 6 inches. What is the area of the circle? 
Recall:  $A=\pi r^2$   and   $C=2\pi r$  

A Circle has a diameter of 10 centimeters. What is the area of the circle?

Recall: $A=\pi r^2$  and  $C=2\pi r$  

A Circle has a diameter of 18 meters. What is the area of the circle? 

Recall:   $A=\pi r^2$  and  $C=2\pi r$  

The area of a circle is  $25\pi$ .  What is the radius?
Recall:  $A=\pi r^2$  and  $C=2\pi r$  

The area of a circle is  $64\pi$ .  What is the radius?
Recall:  $A=\pi r^2$  and  $C=2\pi r$