A tent is made in the form of a frustum A of a right circular cone surmounted by another right circular cone B. The diameter of the ends of the frustum A are 8 m and 4 m, its height is 3 m and the height of the cone B is 2 m. What is the area of the canvas required for the tent?
Answer & explanation
Correct answer: option 2
Slant height of the frustum
$=\sqrt{(2-4)^2+3^2}=\sqrt{13}$
slant height of cone
$=\sqrt{2^2+2^2}=2\sqrt{2}$
Tent canvas required = CSA of frustum + CSA of cone
$=π×\sqrt{13}(4+2)+π×2\sqrt{2}×2=85.77m^2$