Test your understanding of why the area of a circle is \(\pi r^2\), including the circle-to-rectangle idea, radius, circumference, and area formula.

Try to answer the questions before checking the answers at the bottom of the page.

Question 1

What does the area of a circle measure?

A) Distance around the circle
B) Space inside the circle
C) Diameter of the circle
D) Radius of the circle

Question 2

What is the formula for the area of a circle?

A) $2\pi r$
B) $\pi d$
C) $\pi r^2$
D) $r^2$

Question 3

If the radius of a circle is 4 cm, what is the area?

A) $8\pi$ cm²
B) $12\pi$ cm²
C) $16\pi$ cm²
D) $32\pi$ cm²

Question 4

Half of the circumference of a circle is equal to:

A) $2r$
B) $\pi r$
C) $r^2$
D) $2\pi r$

Question 5

What shape does the rearranged circle slices begin to look like?

A) Triangle
B) Square
C) Rectangle
D) Pentagon

Question 6

If the diameter of a circle is 10 m, what is the radius?

A) 2 m
B) 5 m
C) 10 m
D) 20 m

Answers

1. B) Space inside the circle
2. C) $\pi r^2$
3. C) $16\pi$ cm²
4. B) $\pi r$
5. C) Rectangle
6. B) 5 m

Practice

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Continue Learning

1. Length, Area, and Volume: What’s the Difference?
2. Why the Area of a Circle is 𝜋𝑟² (Visual Explanation)

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