Circle Vocabulary and Area Quiz

What is the term for a line segment that extends from the center of a circle to its edge?

• Chord

• Radius

• Circumference

• Diameter

Which of the following statements is true about the diameter of a circle?

• It is half the length of the radius.

• It is equal to the radius.

• It is twice the length of the radius.

• It is unrelated to the radius.

Pi is an irrational number. What does this mean?

• It can be expressed as a simple fraction.

• It has a repeating decimal pattern.

• It is a whole number.

• It continues indefinitely without a repeating pattern.

What approximate value is commonly used for pi in calculations?

• 3.15

• 3.14

• 3.16

• 3.13

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

• A = 2πd

• A = πd

• A = 2πr

• A = πr²

If the radius of a circle is 5 cm, what is the area of the circle using 3.14 for pi?

• 50 cm²

• 25 cm²

• 78.5 cm²

• 100 cm²

In the first example, what is the result of squaring the radius of 5 cm?

• 25

• 20

• 15

• 10

In the second example, if the diameter is 8 cm, what is the radius?

• 2 cm

• 8 cm

• 4 cm

• 6 cm

What is the area of a circle with a diameter of 8 cm using 3.14 for pi?

• 75.36 cm²

• 100.48 cm²

• 50.24 cm²

• 25.12 cm²

What is a key step when given the diameter instead of the radius in area calculations?

• Multiply the diameter by pi.

• Divide the diameter by two to find the radius.

• Subtract the diameter from pi.

• Add the diameter to pi.