Circles 2

Circles 2 - Transcript

spi 3 2 B spi 3 2 L

Arc Length Sectors Sections
Jim Smith JCHS Jim

7

C 2 r C 2 7 C 14

9

A r A 9 A 81

A

B

The length of AB represents a fractional The part of the circle s circumference If the mAB Is 90 then the length of AB is 90 360th 1 4th of the circumference 90 360

A

Find the length of AB
6 B

C 2 r C 2 6 C 12

90 360

Length of AB 12 3 Length

A

60
B

C 2 r C 16

8

AB 60 360 of 16 AB 1 6 16 AB 1 16 61 AB 8 3

Z

120 X 360 360 120 120 240 240

9

Find the length of Find XYZ C 2 r C 18
Y

XYZ 240 of 18 360 360 XYZ 2 18 31 XYZ 12

Sectors are a fractional part of a circle s area of

8

Find the shaded area area A r A 64

Sector area of 64
90 of circle s area 90 360

64 16 16 4

60 60 12

Area r A 144 Area Sector area Sector

60 of circle s area 60 360

A 1 of 144 6 144 24 6

Sections Sections
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AREA OF SECTION AREA AREA OF SECTOR AREA OF TRIANGLE AREA

r

bh bh

Area of section Area area of sector area of triangle area r bh bh
A OF 100

10

25 25
A OF 10 10

50 50
A of circle 100

A OF SECTION OF

25 50 25