Circles, Circles, Circles!

Radius & Diameter

100

What is Radius?

Radius is the distance from the centre of a circle to any point of the circle.

200

What is Diameter?

The distance across a circle measured through its centre.

300

The radius is 14. This is the diameter.

What is 28?

400

The Diameter is 25 meters. What is the Radius?

The Radius is 12.5 meters.

500

The Radius is  81 cm. What is the Diameter?

the Diameter is 162 cm.

Circumference

100

What is Circumference?

Circumference is the distance around a circle.

200

A circle has a diameter of 3 inches.  This is the circumference.

What is 9.42?

300

A circle has a diameter of 102.38 inches.  What is the circumference?

What is 321.47 inches?

400

A circle has a radius of 16 feet.  Find the Circumference.

100.48 feet

500

If the radius is 123.45, this is the circumference.

What is 775.266?

Area

100

What is the formula for area of a circle?

A= pi*r²

200

A circle has a diameter of 16. Find the area.

200.96

300

A circle has a radius of 50 miles. What is the area of the circle TO THE NEAREST MILE?

What is 7854 mi².

400

A pizza is 16 inches long (diameter). It is cut into 4 pieces. Jane eats 3 of the pieces. What is the area of pizza she is eating?

What is 48 pi in²

500

If you diameter is 7.35 what is your area?

What is 42.41?