One radian: the arc equal to the radiusएक रेडियन: त्रिज्या के बराबर चापEk radian: radius ke barabar arc

Fig 3.4 · Class 11 Maths Ch 3 · interactive diagram

Parts and what they mean

• Radius r (त्रिज्या r) — The radius of the circle.
• Radius r (त्रिज्या r) — Second radius ending at the end of the arc.
• Arc of length r (लंबाई r का चाप) — When the arc length equals the radius, the angle at the centre is exactly 1 radian. In general l = rθ.
• 1 radian ≈ 57°16′ (1 रेडियन ≈ 57°16′) — 180° = π radians, so 1 rad = 180°/π ≈ 57°16′ and 1° = π/180 rad ≈ 0.01746 rad.

Original diagram drawn by Simple Learning Hub for NCERT Class 11 Maths Ch 3. Report a mistake