Area of a Circle

What is the relationship between the circumference and area of a circle?

• Both are related to the radius, but circumference is linear (C = 2·π·r) while area is quadratic (A = π·r²).

• Circumference is calculated using the diameter, while area is calculated using the radius.

• Circumference is a measure of the area, while area is a measure of the circumference.

• Both circumference and area are linear functions of the radius.

Find the area of a circle with a diameter of 10 cm.

• 31.42 cm²

• 62.83 cm²

• 78.54 cm²

• 100.00 cm²

How do you convert diameter to radius?

• Multiply the diameter by 2.

• Add 2 to the diameter.

• Divide the diameter by 2.

• Subtract 2 from the diameter.

Find the area of a circle with a radius of 7 cm.

• A = π·(7)² = 153.94 cm² (approximately)

• A = π·(7)² = 140.00 cm²

• A = π·(7)² = 154.00 cm²

• A = π·(7)² = 150.00 cm²

What is the formula for finding the area of a circle?

• A = π·r

• A = 2π·r

• A = π·r²

• A = π·r³

What is the diameter of a circle?

• The distance across the circle through the center, equal to 2 times the radius.

• The distance around the circle, equal to the circumference.

• The distance from one point on the circle to another point on the circle.

• The distance from the center of the circle to any point on the circle.

What is the significance of the number π in geometry?

• It is a constant that represents the ratio of the circumference of a circle to its diameter.

• It is a variable used to calculate the area of a triangle.

• It is a measurement of the angle in a right triangle.

• It is a constant that represents the volume of a sphere.

What is the formula for the circumference of a circle?

• C = 2·π·r

• C = π·d

• C = 2·r

• C = r²·π

What is the area of a circle?

• The amount of space inside of the circle.

• The circumference of the circle.

• The diameter of the circle.

• The radius of the circle.

What is the symbol for pi?

• π

• p

• 3.14

• φ