Circumference, area, perimeter

The diameter of a circle is 5 in. What is the circumference?

• 15 in.

• 31.4 in.

• 3.14 in.

• 15.7 in

The radius of a circle is 4 m.

What is the circumference?

• 25.12 m.

• 12.56 m

• 12 m.

• 251.2 m.

What are the steps to finding the perimeter of a semi-circle?

• find the circumference and divide by 2.

• find the circumference , divide by 2 and subtract the diameter.

• find the circumference, divide by 2 and add the diameter.

A semi-circle has a diameter of 2 m. What is the perimeter?

• 51.4 m.

• 5.14 m.

• 1.14 m.

• 11.4 m.

A semi-circle has a radius of 3 cm. What is the perimeter?

• 152.4 cm.

• 15.42 cm.

• 12.42 cm.

• 6.42cm.

Identify the correct formula for finding the AREA of a circle

•  $A\ =\ \pi r^2$  

•  $A\ =\ \pi d$  

•  $A\ =\ 2\pi r$  

What is the formula for the area of a circle with a radius of 2 cm.?

•  $A=\left(3.14\right)\left(2\right)^2$  

•  $A\ =2\pi r$  

•  $A=\ 2\pi r$