Math · Geometry
Circumference and Area of Circles
Use C = 2πr and A = πr² with π ≈ 3.14 or in terms of π.
- 🎓 Grade 7
- 🧮 Math
- 📐 7.G.B.4
- ❓ 22 questions
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A circle has circumference 31.4 m. What is its diameter? (Use π ≈ 3.14)
- A 5 m
- B 98.6 m
- C 10 m
- D 20 m
31.4 ÷ 3.14 = 10
A circle has radius 3 m. What is its area? (Use π ≈ 3.14)
- A 9.42 m²
- B 113.04 m²
- C 28.26 m²
- D 18.84 m²
A = πr² = 3.14 × 9 = 28.26
A circle has diameter 8 cm. What is its area in terms of π?
- A 64π cm²
- B 16π cm²
- C 4π cm²
- D 8π cm²
r = 4, so A = π × 4² = 16π
A circle has diameter 14 cm. What is its area in terms of π?
- A 7π cm²
- B 196π cm²
- C 14π cm²
- D 49π cm²
r = 7, so A = π × 7² = 49π
A circle has radius 5 cm. What is its circumference? (Use π ≈ 3.14)
- A 78.5 cm
- B 62.8 cm
- C 15.7 cm
- D 31.4 cm
C = 2πr = 2 × 3.14 × 5 = 31.4
A circle has radius 10 in. What is its area? (Use π ≈ 3.14)
- A 1,256 in²
- B 31.4 in²
- C 314 in²
- D 62.8 in²
A = πr² = 3.14 × 100 = 314
The radius of a circle is 4 cm. What is the diameter?
- A 16 cm
- B 12.56 cm
- C 2 cm
- D 8 cm
A half-circle has radius 10 m. What is its area? (π ≈ 3.14)
- A 314 m²
- B 15.7 m²
- C 31.4 m²
- D 157 m²
3.14 × 100 ÷ 2 = 157
A circle has radius 7 ft. What is its area? (Use π ≈ 3.14)
- A 153.86 ft²
- B 21.98 ft²
- C 43.96 ft²
- D 615.44 ft²
A = πr² = 3.14 × 49 = 153.86
A wheel has diameter 2 ft. About how far does it roll in one full turn? (π ≈ 3.14)
- A 6.28 ft
- B 3.14 ft
- C 12.56 ft
- D 2 ft
A circle has radius 3 m. What is its circumference? (Use π ≈ 3.14)
- A 18.84 m
- B 37.68 m
- C 28.26 m
- D 9.42 m
C = 2πr = 2 × 3.14 × 3 = 18.84
A circle has diameter 10 cm. What is its area in terms of π?
- A 5π cm²
- B 100π cm²
- C 25π cm²
- D 10π cm²
r = 5, so A = π × 5² = 25π
A circle has radius 5 cm. What is its area? (Use π ≈ 3.14)
- A 15.7 cm²
- B 78.5 cm²
- C 31.4 cm²
- D 314 cm²
A = πr² = 3.14 × 25 = 78.5
A circle has radius 4 cm. What is its area? (Use π ≈ 3.14)
- A 200.96 cm²
- B 25.12 cm²
- C 50.24 cm²
- D 12.56 cm²
A = πr² = 3.14 × 16 = 50.24
What is the ratio of any circle's circumference to its diameter?
- A 2
- B 2π
- C r
- D π
A circle has radius 6 m. What is its circumference? (Use π ≈ 3.14)
- A 18.84 m
- B 37.68 m
- C 75.36 m
- D 113.04 m
C = 2πr = 2 × 3.14 × 6 = 37.68
A circle has radius 4 cm. What is its circumference? (Use π ≈ 3.14)
- A 12.56 cm
- B 25.12 cm
- C 50.24 cm
C = 2πr = 2 × 3.14 × 4 = 25.12
A circle has diameter 12 m. What is its circumference in terms of π?
- A 36π m
- B 6π m
- C 24π m
- D 12π m
C = πd
A circle has diameter 9 m. What is its circumference in terms of π?
- A 18π m
- B 9π m
- C 4.5π m
- D 20.25π m
C = πd
A circle has radius 10 in. What is its circumference? (Use π ≈ 3.14)
- A 62.8 in
- B 314 in
- C 125.6 in
- D 31.4 in
C = 2πr = 2 × 3.14 × 10 = 62.8
A circle has radius 7 ft. What is its circumference? (Use π ≈ 3.14)
- A 153.86 ft
- B 87.92 ft
- C 43.96 ft
- D 21.98 ft
C = 2πr = 2 × 3.14 × 7 = 43.96
A circle has radius 6 m. What is its area? (Use π ≈ 3.14)
- A 113.04 m²
- B 452.16 m²
- C 37.68 m²
- D 18.84 m²
A = πr² = 3.14 × 36 = 113.04
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