Mathematics for IGCSE & O level - Mensuration (Section 8 - No. 45)
A tower of a castle has walls in the form of a cylinder and a roof in the shape of a cone. The diameter of the tower is 5.6 m and the height of the wall is 12 m. The roof has a height of 6.2 m. What is the total surface area of the tower (excluding the base)?
305.6 m²
325.8 m²
345.1 m²
286.2 m²
स्पष्टीकरण
Surface Area of Cylinder = 2πrh = 2 * π * 2.8 * 12 = 211.1 m². Slant height = √ (2.8² + 6.2²) = 6.79 m. Surface area of cone = πrl = π * 2.8 * 6.79 = 59.8 m². Total surface area = 211.1 + 59.8 = 270.9 m². This does not match any of the answers.