Circumference and Area of a Circle

Today, we will determine how to find the circumference and area of a circle

identify the radius and diameter of a circle

C= the distance around a circle

Formulas for circumference: 

Diameter= double the radius

Radius= half the diameter

 $\pi\ \approx3.14$  

the amount of space a 2D shape takes up

measured in square units  $\left(units^2\right)$  

Remember the formula:

Plug in what you know

  $A=\pi\left(8\right)^2$  

 $A=\ 64\pi$   $cm^2$  

Remember your formula:

Notice: You are given the diameter. But, the formula uses the radius. So, you must divide the diameter by 2, to find the radius. 12/2= 6 inches.

Now, plug in what you know. 

 $A=3.14\left(6\right)^2$  

 $A=3.14\left(36\right)$  

A=113.04  $in^2$