Understanding Circles: Area and Circumference

What is the radius of a circle if its diameter is 10 units?

• 2.5 units

• 20 units

• 5 units

• 10 units

Tags

CCSS.HSG.C.A.2

How do you find the radius from the diameter of a circle?

• Square the diameter

• Divide the diameter by 2

• Multiply the diameter by 2

• Multiply the diameter by π

Using the formula C = πd, what is the circumference of a circle with a diameter of 14 units?

• 43.96 units

• 44 units

• 28 units

• 88 units

Tags

CCSS.HSG.GMD.A.1

If the radius of a circle is 7 units, what is its circumference using C = 2πr?

• 14 units

• 14π units

• 44 units

• 22 units

Tags

CCSS.HSG.GMD.A.1

What formula is used to calculate the circumference of a circle when the radius is known?

• C = πd

• A = πr^2

• C = 2πr

• A = πd^2

Tags

CCSS.HSG.GMD.A.1

A circle's diameter is 20 units. What is its circumference?

• 20π units

• 40 units

• 62.8 units

• 10π units

Tags

CCSS.HSG.GMD.A.1

What is the area of a circle with a radius of 4 units?

• 50.24 square units

• 16π square units

• 12.56 square units

• 25.12 square units

Tags

CCSS.HSG.GMD.A.1

A circle has a diameter of 16 units. What is its area?

• 256π square units

• 128π square units

• 64π square units

• 200.96 square units

Tags

CCSS.HSG.GMD.A.1

If a circle has a radius of 9 units, what is its area?

• 81π square units

• 36π square units

• 18π square units

• 72π square units

Tags

CCSS.HSG.GMD.A.1

What is the area of a circle with a diameter of 10 units?

• 100π square units

• 50π square units

• 25π square units

• 78.5 square units

Tags

CCSS.HSG.GMD.A.1