Question

Find the radius of a sphere whose surface area is 154cm3

Answer 1

Answer:

The radius of a sphere whose surface area 154 sq. cm is 44 cm.

Step-by-step explanation:

Given: The surface area of the sphere is 154 sq cm.

Find: The radius of a sphere.

Formula: The surface area of the sphere $= 4 \pi r^2$ square units.

The surface area of the sphere $= 4 \pi r^2$

[tex]4 \times\frac{22}{7} \times r^2 = 154\\ \frac{88}{7} \times r^2 = 154\\ r^2 = 154 \times \frac{88}{7} \\ r^2 = 22 \times 88\\ r^2 = 1936\\ r = 44 cm[/tex]

So, the radius of a sphere is 44 cm.

Answer 2

Answer:

Radius of sphere is 3.5cm

Step-by-step explanation:

Given that

Surface area of sphere is 154 cu. cm

To find

Radius of sphere

Solution

As we know that

$area \: of \: sphere = 4 \times \pi \times {radius}^{2}$

hence

$154 = 4 \times \frac{22}{7} \times {radius}^{2}$

by multiplication we get

$154 = \frac{88}{7} \times {radius}^{2}$

${radius}^{2} = 154 \times \frac{7}{88}$

${radius}^{2} = 12.25cm$

$radius = \sqrt{12.25}$

hence we get

$radius \: of \: sphere = 3.5cm$