Question

A toy is in the form of a cone of radius $3.5cm$ mounted on a hemisphere of same radius. The total height of the toy is $15.5cm$. Find the total surface area of the toy.

Answer 1

Total Surface area of toy$=$Surface area of hemisphere without base+Surface area of cone without base

Total height $=15.5=r+h$

$h=15.5-3.5=12cm$

$A=2\pi r^2+\pi r\sqrt{r^2+(15.5-r{)}^2}$

$A=2\pi \times {3.5}^2+\pi \times 3.5\sqrt{{3.5}^2+{12}^2}$

$A=214.5c{m}^2$