Question

the surface area of a spere is 98.56 find its diameter

Answer 1

hello Frnd ...


GIVEN AS

Surface area of a Sphere = 98.56 Cm^2

We have to find Diameter.


As we know that, Diameter is twice of the radius i.e d = 2r

Therefore to calculate Diameter we need to find the radius of the Sphere.


As we know

$surface \: area \: = 4\pi {r}^{2} \\ 98.56 = 4\pi {r}^{2} \\ 98.56 \div 4 = \pi {r}^{2} \\ 24.64 = \pi {r}^{2} \\ \\ putting \: \pi = 3.14 \: we \: get \\ 24.64 \div 3.14 = {r}^{2} \\ 7.84 = {r}^{2} \\ \\ \sqrt{7.84} = r \\ 2.8 = r$
hence Radius (r) = 2.8

Therefore Diameter = 2r = 2 × 2.8 = 5.6 cm




hope it helps
jerri

Answer 2

Heya,

Given:-
Surface area of sphere = 98.56cm^2

To find:-
Diameter

Solution:-

Diameter = 2r

So, to find radius (r)

SA = 4πr^2

98.56 = 4 × 22/7 × r^2

98.56 = 88/7 × r^2

98.56 × 7 = 88r^2

689.92 = 88r^2

689.92/88 = r^2

7.84 = r^2

√7.84 = r

2.8 cm = r

As before we mentioned that,

Diameter = 2r

Diameter = 2 × 2.8

Diameter = 5.6cm

Hope my answer helps you :)

Regards,
Shobana