Question

The length of the equator of the globe is 44 cm. Find its surface area.

Answer 1

Hint: In this question it is given that the length of the equator of a globe is 44 cm, so we have to find the surface area of the globe. So to understand it in better way we have to draw the diagram,

So to find the solution we have to know that the length of the equator is nothing but the circumference of the globe. So by using the circumference formula we have to find the surface area of the globe.

Circumference=$2\pi r$ and the surface area=$4\pi r^{2}$.

Where r is the radius of the globe.

Complete step by step answer:

So it is given that the circumference is 44, which implies,

$2\pi r$=44

$\Rightarrow r=\dfrac{44}{2\pi }$

$\Rightarrow r=\dfrac{44}{2\times \left( \dfrac{22}{7} \right) }$  $\,\,\,\because \pi =\dfrac{22}{7}$

$\Rightarrow r=\dfrac{44\times 7}{2\times 22}$

$\Rightarrow r=7$

So we get the radius of the globe is 7 cm.

Now we have to find the surface area of the globe or sphere.

Surface area=$4\pi r^{2}=4\times \dfrac{22}{7} \times 7^{2}=616 cm^{2}$.

Thus the surface area of the globe is 616 $cm^{2}$.

Note: While solving this question you have to know that any globe is considered as a sphere and every formula for a globe (like- surface area, volume, etc) is dependent upon its radius, so at first, you need to find the radius from the condition which is given in the question.