Understanding the Area of a Circle

What is the area of a circle?

• The radius of the circle

• The circumference of the circle

• The amount of space inside the circle

• The diameter of the circle

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

• A = 2πd

• A = πd

• A = 2πr

• A = πr²

What does the 'r' represent in the formula A = πr²?

• Radius of the circle

• Diameter of the circle

• Area of the circle

• Circumference of the circle

What is the approximate value of π used in calculations?

• 3.75

• 3.50

• 3.14

• 3.00

How do you calculate the square of a number?

• Add the number to itself

• Multiply the number by itself

• Divide the number by 2

• Multiply the number by 2

What is the area of a circle with a radius of 5 decimeters?

• 50 square decimeters

• 78.5 square decimeters

• 25 square decimeters

• 100 square decimeters

In the example with a radius of 5 decimeters, what is the value of r²?

• 20

• 15

• 25

• 10

What is the area of a circle with a radius of 9 inches?

• 81 square inches

• 200 square inches

• 254.30 square inches

• 100 square inches

In the example with a radius of 9 inches, what is the value of r²?

• 18

• 27

• 81

• 90

How is the diameter related to the radius of a circle?

• Diameter is half the radius

• Diameter is twice the radius

• Diameter is the same as the radius

• Diameter is unrelated to the radius