Area : Circle

Ever wondered how much cloth I need to cover a circular table ? Did some math there ?

Well, that put simply area of the circle is equal to amount of cloth needed to cover it.

In mathematical terms, area of a circle is the region enclosed within the boundary .i.e circumference.

The formula for Area of a circle is A = πr² , where
π = constant ( 3.142 or 22/7)
r = radius of the circle

Since radius = diameter / 2 , we can rewrite area of circle as ,
A = πd, where
π = constant ( 3.142 or 22/7)
r = diameter of the circle

Just remember these two formulas, and any problem on area of circle can be solved quickly.

Few examples of area of circle questions,
Example 1:
If the length of the radius of a circle is 7 units. Calculate its area.

Solution:
Radius(r) = 7 units(given)
Using the formula for the circle’s area,
Area of a Circle = πr²
Put the values,
A = π (7)²
A =π × 49
A = 22/7 × 49 …… ( π = 22/7, using this for ease of calculation)
A = 154 sq.units.

Example 2:
If the area of a circle is 44 sq. units find its diameter.

Solution:
Area(A) = 44 sq.units(given)
Using the formula for the circle’s area,
Area of a Circle = πd
Put the values,
44 = π × d
44 = 22/7 × d
2 × 7 = d ….. ( cancelling out 22 × 2 = 44)
d = 14 units.

Easy right ? Who said Math was hard !

Just remember the formulae.

Thank you for reading.