A closed-base cylinder of radius 9 cm and height 30 cm has a cone of the same radius and slant heigh

Question

A closed-base cylinder of radius 9 cm and height 30 cm has a cone of the same radius and slant height 15 cm fixed on top. Find the total exposed surface area, using $\pi=3.142$ where needed. Give decimal answers to 2 d.p. $30\text{ cm}$ $l=15\text{ cm}$ $r=9\text{ cm}$ Central section

Accepted Answer

The joined circular face is hidden. Include the cylinder curve, cone curve and bottom circle. Area $=2\pi(9)(30)+\pi(9)(15)+\pi(9^2)=756\pi=2375.35\text{ cm}^2$.

Exposed surface area

Exposed surface area

Solution:

Solution locked