Find the area of any circle given its radius. Essential for land surveying, pizza portioning, graphic design, manufacturing or physics problems involving circular motion.
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Radius of the circle
A = π r²r — radius. π ≈ 3. 1415926535. Square the radius first, then multiply by π.
For circumference use 2πr
Next: circle circumference.
Open this calculator for cases where a small arithmetic slip would otherwise force a full restart around circle segment area.
Keep sector area calculator math tidy when a plan, worksheet, or note set needs one quick calculation.