½r2(θ × π/180 - sinθ) ½r2θ θ/360 × 2πr ½r2sinθ rθ θ/360 × πr2 ½r2(θ-sinθ) πr2 × θ/360 - ½r2sinθ arclength = ½r2(θ × π/180 - sinθ) ½r2θ θ/360 × 2πr ½r2sinθ rθ θ/360 × πr2 ½r2(θ-sinθ) πr2 × θ/360 - ½r2sinθ A(sector) = ½r2(θ × π/180 - sinθ) ½r2θ θ/360 × 2πr ½r2sinθ rθ θ/360 × πr2 ½r2(θ-sinθ) πr2 × θ/360 - ½r2sinθ A(Δ-in-○) = ½r2(θ × π/180 - sinθ) ½r2θ θ/360 × 2πr ½r2θ - ½r2sinθ rθ θ/360 × πr2 ½r2(θ-sinθ) πr2 × θ/360 - ½r2sinθ A(segment) = θ/360 × πr2 ? ½r2sinθ ? ½r2θ ? ½r2sinθ ? ½r2(θ-sinθ) ? ½r2sinθ ? πr2×θ/360 - ½r2sinθ ? ½r2sinθ ? rθ ? ½r2θ ? θ/360 × 2πr ? θ/360 × πr2 ? |