Lesson 3: Areas of Circles — Practice Questions

1. 1. A circular plate has a diameter of 12 inches. What is its area in terms of $\pi$? The area is ___ square inches.

2. 2. A circle has a diameter of 20 feet. What is its area?

   • A. $400\pi sq ft$
   • B. $100\pi sq ft$
   • C. $20\pi sq ft$
   • D. $40\pi sq ft$

3. 3. A circular lid has a diameter of 5 meters. In terms of $\pi$, what is the area of the lid? The area is ___ square meters.

4. 4. A student is asked to find the area of a circle with a diameter of 16 cm. What is the correct first step?

   • A. Divide the diameter by 2 to get the radius.
   • B. Square the diameter.
   • C. Multiply the diameter by $\pi$.
   • D. Multiply the diameter by 2.

5. 5. If you mistakenly use the diameter instead of the radius in the area formula $A=\pi r^2$, your calculated area will be how many times larger than the correct area?

   • A. 2 times larger
   • B. 4 times larger
   • C. 8 times larger
   • D. $\pi$ times larger

6. 6. The lid of a paint bucket is a circle with a radius of 7 inches. Find the area of the lid in square inches. Use 3.14 for $\pi$. The area is ___ square inches.

7. 7. An extra-large pizza is a circle with a radius of 8 inches. Find the area of the pizza in square inches. Use 3.14 for $\pi$. The area is ___ square inches.

8. 8. A circular rug has a radius of 3.5 feet. Find the area of the rug in square feet. Use 3.14 for $\pi$. The area is ___ square feet.

9. 9. A farm sprinkler spreads water in a circle with a radius of 8.5 feet. Find the area of the watered circle in square feet. Use 3.14 for $\pi$. The area is ___ square feet.

10. 10. A circular garden has a radius of 6 meters. Using $\pi \approx 3.14$, what is the area of the garden in square meters? The area is ___ square meters.