7th Grade Circle Area and Circumference Test Questions with Answers

📚 Quick Study Guide

• 📐 The radius ($r$) of a circle is the distance from the center to any point on the circle.
• 📏 The diameter ($d$) of a circle is the distance across the circle through the center. Note: $d = 2r$.
• ➗ Pi ($\pi$) is the ratio of a circle's circumference to its diameter, approximately equal to 3.14159. We often use 3.14 for calculations.
• ♾️ The circumference ($C$) of a circle is the distance around it. The formula for circumference is $C = 2\pi r$ or $C = \pi d$.
• ⏺️ The area ($A$) of a circle is the amount of space it covers. The formula for area is $A = \pi r^2$.
• 💡 Key Tip: Remember to use the correct units! Area is always in square units (e.g., $cm^2$, $m^2$), while circumference is in linear units (e.g., cm, m).

📝 Practice Quiz

1. What is the area of a circle with a radius of 5 cm?
   1. A) 15.7 cm²
   2. B) 31.4 cm²
   3. C) 78.5 cm²
   4. D) 157 cm²
2. What is the circumference of a circle with a diameter of 10 m?
   1. A) 15.7 m
   2. B) 31.4 m
   3. C) 78.5 m
   4. D) 314 m
3. A circle has a circumference of 62.8 inches. What is its radius?
   1. A) 5 inches
   2. B) 10 inches
   3. C) 15 inches
   4. D) 20 inches
4. What is the diameter of a circle with an area of 28.26 ft²? (Use π = 3.14)
   1. A) 3 ft
   2. B) 6 ft
   3. C) 9 ft
   4. D) 12 ft
5. A circular garden has a radius of 8 meters. How much fencing is needed to enclose the garden?
   1. A) 25.12 m
   2. B) 50.24 m
   3. C) 100.48 m
   4. D) 200.96 m
6. If the radius of a circle is doubled, how does the area change?
   1. A) The area remains the same.
   2. B) The area doubles.
   3. C) The area triples.
   4. D) The area quadruples.
7. A pizza has a diameter of 12 inches. What is the area of the pizza?
   1. A) 37.68 in²
   2. B) 75.36 in²
   3. C) 113.04 in²
   4. D) 452.16 in²