Area and Circumference of Circles

What is the name of the line that goes from one end of the circle to the other and crosses the center point?

• Area

• Diameter

• Circumference

• Radius

The radius is....

• a line that crosses through the center and touches each edge 

• the center point of a circle 

• a line from the center point to the edge of the circle

• an element in science

Find the perimeter of the figure.  Use 3.14 for π!

• 20.57 in.

• 16 in.

• 28.57 in.

• 14.28 in.

What is the area of a quarter circle if the diameter is 14 cm?

• 12.25π cm²

• 49π cm²

• 14π cm²

• 3.5π cm²

If the area of circle is 100π.  Find the radius of the circle.

• 10π

• 10

• 50

• 50π

What is the perimeter of this semi circle?

• 8π cm

• 4π cm

• 2π cm

• 16π cm

If the problem ask you to find the distance around a circle, which formula should you use?

• r = d/2

• d = 2r

• C = πd

• A = πr²

What is the radius of this circle?

• 18 in

• 36 in

• 9 in

Find the circumference of a circle that has a radius of 3ft.

• about 18.84 ft.

• about 10 ft

• about 9 ft

• about 16.26 ft

What is the circumference of a circle with a radius of 12.7 m? 

• 79.76 m

• 80.34 m

• 14.56 m

• 80.00 m