To recall, the area is the an ar that populated the form in a two-dimensional plane. In this article, friend will find out the area of a circle and the formulas for calculating the area of a circle.
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What is the Area that a Circle?
The area that the one is the measure up of the room or an ar enclosed inside the circle. In an easy words, the area of a one is the total number of square units inside that circle.
For example, if you draw squares of dimensions 1cm by 1cm inside a circle. Then, the total number of full squares situated inside the circle represents the area that the circle. We deserve to measure the area of a circle in m2, km2, in2, mm2, etc.
Formula because that the Area of a Circle
The area the a circle deserve to be calculated using three formulas. This formulas are used depending ~ above the details you space given.
Let us talk about these formulas because that finding the area of a circle.
Area of a circle utilizing the radius
Given the radius that a circle, the formula because that calculating the area of a circle states that:
Area of a circle = πr2 square units
A = πr2 square units
Solution
Given the diameter,
A = πd2/4 square units
= 3.14 x 502/4
= (3.14 x 50 x 50)/4
=1962.5 cm2
Example 7
Calculate the area of a dinner plate, which has actually a diameter the 10 cm.
Solution
A = πd2/4 square units
= 3.14 x 102/4
= (3.14 x 10 x 10)/4
= 78.5 cm2
Example 8
The diameter of a circular key is 20 cm. Uncover the size of a square plate that will have actually the same area as the one plate.
Solution
Equate the area the the circle come the area the the square
πd2/4 = s2
3.14 x 202/4 = s2
s2 =314
Find the square source of both sides to get,
s = 17.72
Therefore, the size of the square plate will certainly be 17.72 centimeter by 17.72 cm.
Example 9
Find the diameter that a circle through an area the 156 m2.
Solution
A = πd2/4
156 = 3.14d2/4
Multiply both sides by 4.
624 = 3.14d2
Divide both sides by 3.14.
198.726 = d2
d = 14.1 m
Thus, the diameter that the circle will certainly be 14.1 m.
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Area of a circle making use of the circumference
As we currently know, the circumference of a circle is the distance around a circle. It is possible to calculate the area that a circle offered its circumference.