Unit 3 Circumference practice

What is the formula for the circumference of a circle?

• π/2

• πr

• dπ

• d/π

If the radius of a circle is 5 cm, what is its circumference?

• 47.1 cm

• 62.8 cm

• 18.5 cm

• 31.4 cm

If the diameter of a circle is 12 cm, what is its circumference?

• 9.42

• 24.141

• 37.699

• 18.85

What is the relationship between the radius and the diameter of a circle?

• The diameter is equal to the radius.

• The diameter is half of the radius.

• The diameter is three times the radius.

• The diameter is twice the radius.

If the radius of a circle is 30 cm, what is its Circumfernce?

• 15 cm

• 60 cm

• 188.4 cm

• 94.2 cm

If the circumference of a circle is 50 cm, what is its diameter?

• 35

• 12.5

• 25

• 7.957747154594767

What is the constant of proportionality of the circumference of a circle to its diameter?

• pi (π)

• 4

• 3

• 2

If the circumference of a circle is doubled, how does it affect the radius?

• The radius remains the same.

• The radius is tripled.

• The radius is doubled.

• The radius is halved.

If the diameter of a circle is tripled, how does it affect the circumference?

• It doubles.

• It quadruples.

• It remains the same.

• It triples.

If the radius of a circle is halved, how does it affect the circumference?

• Doubled

• Remains the same

• Quadrupled

• Halved