This document contains examples of calculating arc lengths, sector areas, and section areas of circles. It demonstrates how to find the arc length or sector area as a fraction of the total circumference or total area of the circle based on the central angle. It also shows how to calculate the area of a section by subtracting the area of a triangle from the area of the corresponding sector. Key formulas used include the circumference formula C=2r, the area formula for a circle A=r^2, and the area formula for a triangle A=1/2bh.
4. A
B
The length of AB represents a
fractional part of the circles
circumference. If the mAB Is 90属,
then the length of AB is 90/360th
(1/4th) of the circumference.
5. A
B
6
Find the length of AB
C = 2 r
C = 2 6
C = 12
Length of AB = 村揃12 = 3
90/360 = 村
6. A
B
60属
8
C = 2r
C = 16
AB = 60/360 of 16
AB = 1/6 揃 16
AB = 1 揃 16
6 1
AB = 8
3
7. X Y
Z
120属
Find the length of
XYZ
9
XYZ = 240 of 18
360
XYZ = 2 揃 18
3 1
XYZ = 12
360属
- 120属
240属
C = 2r C = 18
