Question

Area of the sector of circle of angle theta and radius 'r'is

Answer 1

As you may remember from geometry, the area A of a circle having a radius of length r is given:

\small{ A = \pi r^2 }A=πr

2

The circumference C (that is, the length around the outside) of that same circle is given by:

\small{ C = 2\pi r }C=2πr

These are the formulas give us the area and arc-length (that is, the length of the "arc", or curved line) for the entire circle. But sometimes we need to work with just a portion of a circle's revolution, or with many revolutions of the circle. What formulas do we use then?

Answer 2

$\pi \: r { \: }^{2} \: \: \frac{angle}{360}$