Area of a circle

Radius

100

If the diameter is 12cm, what is the radius?

6cm

200

If the diameter is 30m, what is the radius?

15m

300

If the diameter is 78m, what is the radius?

39m

400

If the diameter is 101.6cm, what is the radius?

50.8cm

500

If the diameter is 548.9m, what is the radius?

274.45m

Diameter

100

If the radius is 5cm, what is the diameter?

10cm

200

If the radius is 16cm, what is the diameter?

32cm

300

If the radius is 75m, what is the diameter?

150m

400

If the radius is 99.9mm, what is the diameter?

199.8mm

500

If the radius is 54.21km, what is the diameter?

108.42km

Area 1

100

If the radius of a circle is 2mm, what is the area? (round to one decimal place)

12.6mm²

200

If the radius of a circle is 10m, what is the area? (round to the whole number)

314m²

300

If the radius of a circle is 31cm, what is the area? (round to one decimal)

3017.54cm²

400

If the radius of a circle is 11.1m, what is the area? (round to one decimal)

386.9m²

500

If the radius of a circle is 14.4km, what is the area? (round to one decimal)

651.1km²

Area 2

100

If the diameter of a circle is 25cm, what is the area? (round to one decimal)

490.6cm²

200

If the diameter of a circle is 64cm, what is the area? (round to one decimal)

3215.4cm²

300

If the diameter of a circle is 45.5m, what is the area? (round to one decimal)

1625.1m²

400

If the diameter of a circle is 123.45cm, what is the area? (round to one decimal)

11963.3cm²

500

If the diameter of a circle is 21.44m, what is the area? (round to one decimal)

360.8m²

Finding radius

100

Find the radius when the area is 52cm² 

4.1cm

200

Find the radius when the area is 32m²

3.2m

300

Find the radius when the area is 65.2cm²

4.6cm

400

Find the radius when the area is 72.88m²

4.8m

500

Find the radius when the area is 108.9cm²

5.9cm