The diameters of the top and bottom of a frustum of a cone are 6cm and
15cm respectively. If the height of the frustum is 30cm, calculate (i) the
curved surface area (ii) the volume of the frustum. DIAGRAM NEEDED
Note: what is given is the diameter and not the radius
(i) Curved Surface Area = π(R1 + R2) * √(h2 + (R1 - R2)2)
= π(6 + 15) * √(302 + (6 - 15)2)
= π(21) * √(900 + 81)
= π(21) * √981
= 21π * 31.3
= 663.3π cm2
(ii) Volume of the Frustum = (1/3)πh(R12 + R22 + (R1 * R2))
= (1/3)π(30)(62 + 152 + (6 * 15))
= (1/3)π(30)(36 + 225 + 90)
= (1/3)π(30)(351)
= 3510π cm3