Formulae and equations for finding the area and circumference of circles, area of sectors, and length of arcs; examples working backward from area to find the radius, diameter, and circumference.
0:00:00 - Equation for perimeter of a circle
0:01:00 - Equation for area of a circle
0:01:32 - Examples finding area and circumference of a circle given radius and diameter
0:04:55 - Examples finding radius, diameter, and circumference given area
0:08:10 - Equation for area of a sector of a circle
0:09:15 - Examples finding the area of a sector of a circle
0:13:05 - Equation for length of an arc of a circle
0:13:41 - Examples finding the length of an arc of a circle