This clip revisits some of the essential points in the lesson on angles, arcs and sectors, including angle measurement and special angle relationships that occur when lines intersect. The clip also mentions angle measurement in circles, and explains...
This clip looks at the sector, a fraction of a circle's area formed by a central angle and its arc. "We can find the area of a sector," the clips explains, "
by multiplying the ratio of the central angle to the circle by the area of the circle."