Circle Calculator (Advanced)
Calculate circle area, circumference, diameter, and sector area from the radius. Includes arc length computation.
deg
Surface
78.5398
Circonférence31.4159
Diamètre10.0000
Arc Length7.8540
Formule
## Circle Calculations ### Formulas - **Area** = pi × r² - **Circumference** = 2 × pi × r - **Sector Area** = pi × r² × (angle / 360) - **Arc Length** = 2 × pi × r × (angle / 360) A sector is a "pie slice" of the circle defined by a central angle.
Exemple Résolu
A circle with radius 5, find area and a 90-degree sector.
- 01Area = pi × 25 ≈ 78.5398
- 02Circumference = 2 × pi × 5 ≈ 31.4159
- 03Sector area = 78.5398 × 90/360 ≈ 19.6350
- 04Arc length = 31.4159 × 90/360 ≈ 7.8540
Questions Fréquentes
What is a sector?
A sector is the region between two radii and an arc. Think of it as a "pie slice" of the circle.
How do I find the area if I know the diameter?
Divide the diameter by 2 to get the radius, then use A = pi × r². Alternatively, A = pi × d²/4.
What is the relationship between arc length and sector area?
Both are proportional to the central angle. Sector area = (1/2) × r × arc length.
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