Area Formulas and Circumference

Find the area of the circle, giving your answer to 1 decimal place.

• 113.1cm²

• 28.3cm²

• 6.3cm²

• 37.7cm²

Find the area of the circle, giving your answer to 1 decimal place.

• 78.5cm²

• 19.6cm²

• 19.6m²

• 78.5m²

Find the area of the circle, giving your answer to 1 decimal place.

• 154.0cm²

• 38.5cm²

• 38.4cm²

• 153.9cm²

Another use for pi?

• circumference of a circle

• desert after dinner

• triangle bisect line

• square root

Ethan measured a circular lid and found d, the diameter, was 8 inches and C, the circumference, was 25 inches. Which expression represents an approximate value for pi?

What two formulas can you use to find the circumference?

• C = π·d

• C = π·r²

• C = 2·π·r

• C = d²

Find the circumference of the circle.

• 31.4 cm

• 78.5 cm

• 314 cm

• 15.7 cm

Find the circumference of the circle.

• 38.47 cm

• 10.99 cm

• 43.96 cm

• 21.98 cm

Find the area of the circle, giving your answer to 1 decimal place.

• 201.1cm²

• 201.0cm²

• 804.2cm²

• 804.2m²

What number is pi?

• 41

• 00

• 3.14

• 5.14