Perimeter, Area & Circumference

Which 2 formulas can be used to calculate the Circumference of a circle?

• C=2r

• C=2πr

• C=πd

• C=r^2

If the diameter of a circle is 10 cm, what is the radius?

• 12 cm

• 5 cm

• 8 cm

• 3 cm

Calculate the circumference of a circle with radius 5 cm. (Use π=3.14)

• 10.5 cm

• 31.4 cm

• 25.6 cm

• 15.7 cm

What is the formula to calculate the Area of a circle?

• A = 0.5πr^2

• A = 2πr

• A = r^2

• A = πr^2

If the radius of a circle is 6 cm, what is the diameter?

• 8 cm

• 12 cm

• 10 cm

• 14 cm

If C=πd, then what is the ratio for π?

• π=r/C

• π=C/d

• π=d/C

• π=d/r

Find the circumference of a circle with diameter 12 cm. (Use π=3.14)

• 37.68 cm

• 40.82 cm

• 15.92 cm

• 24.56 cm

Calculate the area of a circle with radius of 8 cm. (Use π=3.14)

• 100.48 cm^2

• 250.64 cm^2

• 150.72 cm^2

• 200.96 cm^2

What is the relationship between diameter and radius?

• The diameter is equal to 2 times the radius.

• The diameter is always smaller than the radius.

• The diameter is three times the radius.

• The diameter is half the radius.

To find the perimeter of a square, you can __ all the sides, or do 4s