Topic Details (Notes format)

How to Find the Arc Length of a Circle

Subject: Mathematics

Book: Maths Mastery

Arc length measures the distance along the circle’s circumference for a given central angle. The formula is (θ/360°) × 2πr if θ is in degrees, or (θ/2π) × 2πr if θ is in radians. For instance, for a 90° arc in a circle of radius 4 cm, the length is (90/360) × 2π × 4 = (1/4) × 8π = 2π cm. Arc length comes up in mechanical gears, track layouts, or partial circular fences. Understanding how to translate angles into actual arc distances is crucial for geometry applications that require precise measurement of curved lines.

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