Another prevalent kind of simple closed
curve is a circle. Circles are geometric
figures whose points all lie the same
distance from a given point, the circle's
center.They are not polygons, because
they are not made up of segments.
Points that lie in the same line, like those
in a segment, are never equidistant (an
12. FORMULA’S OF
CIRCLES-1*Diameter = 2 x radius of circle
2*Area of Circle:
area = PI r2
3* Circumference of Circle = PI x diameter = 2 PI x radius
where PI = PI = 3.141592...
4* Length of a Circular Arc: (with central angle theta).
if the angle theta is in degrees, then length = theta x
(PI/180) x r
if the angle theta is in radians, then length = r x theta
13. FORMULA’S OF
CIRCLES-5* Area of Circle Sector: (with central angle theta)
if the angle theta is in degrees, then area =
(theta/360)x PI r2
if the angle theta is in radians, then area =
((theta/(2PI))x PI r2