Mathematics for IGCSE & O level - Mensuration (Section 8 - No. 49)
A cone has a base radius of 5cm and a perpendicular height of 12cm. Calculate for curved surface area.
154.5 cm²
204.2 cm²
188.5 cm²
254.4 cm²
คำอธิบาย
CSA = πrs. To get s, √(h² + r²) = √(12² + 5²) = 13. CSA ≈ π * 5 * 13 = 204.2 cm²