Understanding the Area of a Circle

What is the formula used to calculate the area of a circle?

• A = πd

• A = 2πr

• A = 2πd

• A = πr²

If the radius of a circle is 5 decimeters, what is the area?

• 25 square decimeters

• 50 square decimeters

• 100 square decimeters

• 78.5 square decimeters

What is the approximate value of π used in the calculations?

• 3.50

• 3.75

• 3.14

• 3.00

For a circle with a radius of 9 inches, what is the calculated area?

• 200.30 square inches

• 300.30 square inches

• 254.30 square inches

• 150.30 square inches

How do you find the radius if the diameter is given?

• Square the diameter

• Divide the diameter by 2

• Subtract 2 from the diameter

• Multiply the diameter by 2

What is the area of a circle with a diameter of 12 inches?

• 113.04 square inches

• 120.04 square inches

• 130.04 square inches

• 140.04 square inches

What is the formula for the area of a circle when the diameter is given?

• A = πd/2

• A = πd²

• A = π(d/2)²

• A = 2πd

What is the key takeaway about the area of a circle?

• Area is the diameter of the circle.

• Area is the space inside the circle.

• Area is the radius of the circle.

• Area is the perimeter of the circle.

Which value of π is used in both formulas discussed?

• 3.14

• 3.75

• 3.00

• 3.50

What should you do if the diameter is given instead of the radius?

• Multiply the diameter by 2 to get the radius.

• Use the diameter directly in the formula.

• Ignore the diameter and assume a radius.

• Convert the diameter to radius by dividing by 2.