Question

find the ratio of CSA and TSA of a hemisphere​

Answer 1

Step-by-step explanation:

Hey mate .

========

Let,

The radius of both the hemisphere and sphere be 'r'

We know,

Surface area of the sphere = \frac{4}{3} \pi \: r {}^{3}

3

4

πr

3

And,

Surface area of the hemisphere = \frac{2}{3} \pi \: r {}^{3}

3

2

πr

3

So, The ratio of total surface area of a sphere and a solid hemisphere of same radius

= \begin{lgathered}\frac{ \frac{4}{3}\pi \: r {}^{3} }{ \frac{2}{3} \pi \: r {}^{3} } \\ \\ = \frac{2}{1}\end{lgathered}

3

2

πr

3

3

4

πr

3

=

1

2

= 2:1

Hope it helps !!

Answer 2

Answer:

of a hemisphere: K = (2πr2) + (πr2) = 3πr.

π * r2,