Circle Circumference and Area

What are the formulas for finding the circumference of a circle?

• C = Pi * r^2

• C = Pi * d

• C = 2 * Pi * r

• C = Pi / d

• C = Pi (r) (r)

What does 'r squared' mean in the context of finding the area of a circle?

• r divided by 2

• 2 times r

• r times r

• Pi times r

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

• Radius is half the diameter

• Diameter is double the radius

• Diameter is half the radius

• Radius is double the diameter

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

• A = Pi * r

• A = Pi * d^2

• A = Pi * d

• A = Pi * r^2

What common mistake do students make when learning how to find the area of a circle?

• Using the diameter instead of the radius

• Squaring the diameter instead of the radius

• Thinking r squared is the same as 2 times r

• Forgetting to multiply by Pi

How can the circumference formula be rewritten using the radius?

• C = Pi * r

• C = Pi * 2 * d

• C = Pi * 2 * r

• C = Pi / 2 * r

What is the circumference of a circle if the radius is 8 meters?

• 50.24 meters

• 25.12 meters

• 200.96 meters

• 100.48 meters

What is the area of a circle if the radius is 8 meters?

• 100.48 meters squared

• 25.12 meters squared

• 50.24 meters squared

• 200.96 meters squared

What is the diameter of the Earth used to calculate its circumference?

• 40,055 km

• 12,750 km

• 24,000 km

• 6,375 km

What is the total area of a pizza with a diameter of 24 inches?

• 113.04 square inches

• 452.16 square inches

• 226.08 square inches

• 904.32 square inches