Question

The curved surface area of a hemisphere is 77cm square then what will be the radius of the hemisphere

Answer 1

thus according to my solution r=7/2 cm, if you like this plz make it as brain list

Answer 2

$let \: the \: radius \: of \: the \: hemisphere = r$
$therefore \: curved \: surface \: area \: of \: the \: hemisphere = 2\pi \times r {}^{2}$
$but \: given \: area \: is \: 77cm {}^{2}$
$therefore \: 2\pi \times r {}^{2} = 77$
$or \: \: 2 \times \frac{22}{7} \times r {}^{2} = 77$
$r {}^{2} = \frac{77 \times 7}{2 \times 22}$
$r {}^{2} = \frac{7 \times 7}{2 \times 2}$
$r {}^{2} = \frac{49}{4}$
$r = \sqrt{ \frac{49}{4} }$
$r = \frac{7}{2 \: } cm$
$r = 3.5cm$
hope it helps..