In the below figure, the shaded region I represents a ______ and region II represents a ______.
A region in the interior of a circle enclosed by an arc on one side and a pair of radii on the other two sides is called a sector. So, region I is a sector.
A region in the interior of a circle enclosed by a chord and an arc is called a segment of the circle. So, region II is a segment.
Hence, region I shows a sector and region II shows a segment.