Circles, Circles, Circles!

Circle Vocabulary

100

The distance from the center of a circle to the outside, also half of the diameter

What is radius

200

The longest part in a circle. From one edge to the other through the center. 

What is the Diameter

300

The distance around the circle.

What is circumference?

400

The total amount of space inside of a circle

What is the area?

500

3.14 or 22/7

What is pi?

Finding Radius

100

The Diameter of this circle is 5 cm. What is the radius?

What is 2.5cm?

200

The diameter is 12 feet. What is the radius?

What is 6 feet

300

The diameter of this circle is 27 inches. What is the radius?

What is 13.5 inches

400

The diameter of this circle is 437 miles. What is the radius?

What is 218.5 miles?

500

The diameter is 25.12 mm. What is the radius?

What is 12.56mm?

Finding Diameter

100

The radius of this is 5 in. What is the diameter?

What is 10 in

200

The radius of this circle is 2.5 feet. What is the diameter?

What is 5 feet

300

The radius of this circle is 15.7 in. What is the diameter?

What is 31.4 in

400

The radius of this circle is 18.84 cm. What is the diameter?

What is 37.68 cm

500

The radius of this circle is 194.68 mi. What is the diameter?

What is 389.36 mi?

Finding Area

100

What formula is used to find the area of a cirlce?

What is A = π·r² or A = 3.14·r² ?

200

The radius of this circle is 3 in. What is the area?

What is 28.26 in²

300

The radius of this circle is 21 feet. What is the area?

What is 1384.74 feet²

400

The diameter is 30 mm. What is the area?

What is 706.5mm²?

500

The diameter is 25.12in. What is the area?

What is 495.35in²?