Let’s solve each circle area problem step by step.
We use the formula for area of a circle:
Area = π × r²
where
r is the radius, and we’ll use
π ≈ 3.14 unless told otherwise.
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Problem 1: Radius = 5 cm
Area = 3.14 × 5² = 3.14 × 25 =
78.5 cm²
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Problem 2: Radius = 9 in
Area = 3.14 × 9² = 3.14 × 81 =
254.34 in²
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Problem 3: Diameter = 6 ft → so radius = 6 ÷ 2 = 3 ft
Area = 3.14 × 3² = 3.14 × 9 =
28.26 ft²
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Problem 4: Radius = 4 m
Area = 3.14 × 4² = 3.14 × 16 =
50.24 m²
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Problem 5: Diameter = 10 yd → radius = 10 ÷ 2 = 5 yd
Area = 3.14 × 5² = 3.14 × 25 =
78.5 yd²
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Problem 6: Diameter = 8 km → radius = 8 ÷ 2 = 4 km
Area = 3.14 × 4² = 3.14 × 16 =
50.24 km²
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Problem 7: Radius = 3.5 mi
Area = 3.14 × (3.5)² = 3.14 × 12.25 =
38.465 mi²
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Problem 8: Diameter = 12 mm → radius = 12 ÷ 2 = 6 mm
Area = 3.14 × 6² = 3.14 × 36 =
113.04 mm²
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Problem 9: Radius = 2.5 ft
Area = 3.14 × (2.5)² = 3.14 × 6.25 =
19.625 ft²
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Final Answer:
1) 78.5 cm²
2) 254.34 in²
3) 28.26 ft²
4) 50.24 m²
5) 78.5 yd²
6) 50.24 km²
7) 38.465 mi²
8) 113.04 mm²
9) 19.625 ft²
Parent Tip: Review the logic above to help your child master the concept of area of circles worksheet pdf.
