Question

What is the area of the circle with a radius of $3cm$?

Answer 1

Hint: This is one of the basic questions related to circles along with the finding of perimeter. We are given with the radius of the circle. We have to find the area only. We have the formula in the section area and perimeter of mathematics. We will use that formula and by placing the given dimension values we will find the answer.

Formula used:
Area of circle(A)= \[\pi {r^2}\]
Where r is the radius of the given circle and pi is the constant of the value equals to \[\dfrac{{22}}{7}\,or\,3.14\] (if not given)

Complete step by step solution:
Given that the radius of the circle is 3cm.
Now using the formula mentioned above;
Area of circle: \[\pi {r^2}\]
Now substitute the value of r and pi;
\[ = \dfrac{{22}}{7} \times 3 \times 3\]
On multiplying we get,
\[ = \dfrac{{22 \times 9}}{7}\]
Taking the product,
\[ = \dfrac{{198}}{7}\]
On dividing we get,
\[ = 28.28c{m^2}\]
This is the area of the circle \[ = 28.28c{m^2}\].

Note:
Note that the radius is given to us; we just need to use the formula. If we are given the diameter then we would use the diameter or we will find the radius by dividing it by 2. Area of the circle is the space occupied by it. And if the volume term is used then it is for the three-dimensional shape that is sphere.
Don’t forget to write the unit of the quantity. Here the dimensions are in cm so the unit of the area obtained is also in cm.