Question

the surface area of the small dome (without base ) is found to be 308 sq m . find its radius ...

please answer the question..​

Answer 1

Answer:

Radius = 7 cm

Step-by-step explanation:

In a dome (or hemisphere) the height of dome is equal to it radius

$surface \: area \: of \: dome \: = 2 \times \pi \times {r}^{2}$

$308 = 2 \times \frac{22}{7} \times {r}^{2}$

$154 = \frac{22}{7} \times {r}^{2}$

$\frac{154 \times 7}{22} = {r}^{2}$

$49 = {r}^{2}$

$r = \sqrt{49}$

$r = 7 \: cm$

Answer 2

Given :

Curved surface area of the cone =308cm

2

and Slant height or l=14 cm.

Curved surface area of the cone =πrl

308=

7

22

×r×14

r=

(22×14)

(308×7)

r=7cm

Total surface area of the cone =πr(r+l)

=(

7

22

×7)(7+14)

=22×21

Total surface area of the cone =462cm

2

So, the radius of the base of the cone is 7 cm and the total surface area of the cone is 462cm

2

..

I think wrong answer

(copied from toppr