Circumference

Circumference

What is a Circle?

Parts of a Circle

Center
Radius (distance from center to a point on the circle)
Diameter (distance from a point on the circle through the center to another point on the circle)

 $Diameter\ =\ 2\times Radius$  
 $Radius=Diameter\div2$  

Multiple Choice

12 inches in this circle represents its

• radius

• diameter

Multiple Choice

14cm in the circle represents its

• radius

• diameter

Fill in the Blank

What is the length of the diameter of the circle?

Fill in the Blank

What is the length of the radius of the circle?

Finding Circumference given radius

 $C=2\pi r$  
 $C=2\times3.14\times12$  
 $C=75.36\ ft$  

Finding Circumference given diameter

 $C=\pi d$  
 $C=3.14\times14$  
 $C=43.96\ cm$  

Multiple Choice

Find the circumference of the circle

• 50.24 yd

• 25.12 yd

• 11.14 yd

Multiple Choice

Find the circumference of the circle

• 18.84 cm

• 75.36 cm

• 37.68 cm

Multiple Choice

Find the circumference of the circle whose radius is 4 in

• 12.56 in

• 25.12 in

• 50.24 in

Multiple Choice

Find the circumference of the circle whose diameter is 10 m

• 31.4 m

• 62.8 m

• 15.7 m

Circumference

Now go onto slide 6 and complete today's assignment.

If you have questions, ask for help!