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 $=\pi r\ell +2\pi r^2$

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

$\pi r\ell =\pi \times 3.5\times \sqrt{156.25}$

$=\pi \times 3.5\times 12.5$

$=\frac{962.5}{7}=137.5$

$2\pi r^2=2\times \pi \times {3.5}^2=2\times \frac{22}{7}\times {3.5}^2=77$

$\therefore$ Total curved S.A $=77+137.5=214.5sq.cm$