1. Vocabulary: SECTOR of a circle: a region bounded by an arc of the circle and the two radii to the arc’s endpoints SEGMENT of a circle: a part of a circle bounded by an arc and the segment joining its endpoints

2. Area of a Sector of a Circle Area of a Circle: πr 2 Area of a Sector of a Circle: The area of a sector of a circle is the product of the area and (measure of arc/360) Area of sector AOB = m AB * πr 2 360

3. Area of a Sector of a Circle Area of sector AOB = m AB * πr 2 360 Area of sector AOB = 130 * π(4) 2 360 Area of sector AOB = 18.15 sq units A B O 4 130 0

4. Area of a Sector of a Circle Area of sector AOB = m AB * πr 2 360 Area of sector AOB = A B O 10 40 0

5. Area of a Segment of a Circle A circle has a radius of 10 cm. Find the area of the smaller segment of the circle determined by a 90 0 arc. A B O 10

6. Area of a Segment of a Circle A circle has a radius of 12 cm. Find the area of the smaller segment of the circle determined by a 60 0 arc. A B O 12 60 0