This document discusses calculating arc length and the area of sectors in circles. It provides examples of finding the length of edging for a flower bed shaped as a quadrant of a circle and the area of the flower bed sector. Another example calculates the area of the silver part of an earring pendant shaped as a sector. More practice questions are provided to find the arc length and area of sectors with given radius and central angle measurements.

1. Arc length and the area of sectors
Word problem

2. Objectives:
• To find the arc length and area of sectors

4. Architecture

5. Any work field associat-
ed with using computers

6. Race track designers

7. Pie charts

8. Art

9. Dart board

10. • To find the length of an arc:

12. • To find the area of a sector:

14. Q7 page 276
A flower bed is a quadrant of a circle.
a) Find the length of edging needed for the curved
edge of the bed.
b) Find the area of the flower bed.

16. a)Length of arc
= 90 x 2 x 3.14 x 1.9= 2.983
Length of edging needed= 2.983m
360

17. b) Area of sector
= 90 x 3.14 x 1.9 x 1.9= 2.83385
Area of the flower bed= 2.83385m
360
2

18. Try this
A silver earring pendant is part of a sector of a
circle. Find the area of the silver.

19. Area of the entire sector= 60 x 3.14 x 16 x 16=
360
133.973mm2
Area of the white part= 60 x 3.14 x 12 x 12=
360
75.36mm2
Area of the silver part=
= 58.613mm2
A of the entire sector – A of the white part
= 133.973 – 75.36

20. More questions
1)Radius: 48cm,Angle at centre: 70
a) Find the arc length.
b) Calculate the area of the given sector.
2) A pumpkin pie is made in a mini pie pan
measuring 5 inches in diameter. It is cut into 4
equal slices. What is the area of one piece of the
pie?
O