1. Warm-up Find the circumference and area of the following circles: R = 7 ft D = 20 in

2. Arc Length & Sector Area Unit 5.3

3. Finding Arc Length Arc length is a piece of the circumference. r xoxo

4. Calculate the length of the arc 75 0 r = 8 cm Multiply your answer by the fraction of the circle you do have. cm Arc Length =

5. YOUR TURN! Calculate the length of the arcs 85 0 20 0 316 0 275 0 r = 6cm r = 4cm r = 8cm r = 3.5cm P = 8.90 cm P = 54.12 cm P = 1.40 cm P = 17.80 cm

6. Given the ‘other’ angle. Calculate the arc length of the RED sector 67 0 r = 7 cm First, find the angle we NEED. Arc Length = cm

7. YOUR TURN! r = 9cm 88 o Arc = 42.73 cm

8. 75 0 r = 8 cm Multiply your answer by the fraction of the circle you do have. Calculate the area of the sector cm 2 Sector Area =

9. Calculate the area of the sectors below: 85 0 20 0 316 0 275 0 r = 6cm r = 4cm r = 8cm r = 3.5cm A = 26.70 cm 2 A = 2.79 cm 2 A = 176.49cm 2 A = 29.40 cm 2

10. Given the ‘other’ angle. Calculate the sector area of the RED sector 67 0 r = 7 cm First, find the angle we NEED. Sector Area = cm

11. This is a diagram of a pond, with a concrete path around it. If the diameter of the pond is 5 feet, and the path is 1 foot wide, what is the area of the concrete?

12. The width of a CD is 2 cm, and the diameter of the center hole is 4 cm. The case is 8 cm wide and tall. What area of plastic is seen?