Distance around the circle

2 r = Cor

d = C

Find the circumference.

in. 6.28 C m 33in.8.89C

Portion of the circumference

P

A

B3602

mAB

r

ABlength

3.82 m60º50º

5cm

3602

mAB

r

ABlength

360

50

52

length

38.1

360

60

2

82.3

r

647.3r

647.32 C

A = r2

ANSWERS WILL BE IN SQUARE UNITS

6.8

Find the area.

If S has a circumference of 10 inches, find the area of the circle to the nearest hundredth.

C = 2r10 = 2r

5 = r

A = r2

A = 52A = 25A =

in2

Find the area of the shaded region.

188.49in2

6 in

2 in

A = 22A = 82

A = 4

A = 12.57in2

A = 64

A = 201.06in2

A shaded = A – A= 201.06 - 12.57 =

SECTOR: region bounded by two radii of the circle and their

intercepted arcR

O

Q

Area of a Sector

2

sec

360

Area of tor RQ mRQ

r

60°

120 °

6 cm

7 cm

Q

R

Q

R

218.85cm

251.31cm

2

60

(6) 360

Area

2

sec

360

Area of tor QR mQR

r

2

sec

360

Area of tor QR mQR

r

2

120

(7) 360

Area

A SEGMENT is a region bounded by a chord and its intercepted

arc

A segment is a minor segment if the

intercepted arc is less than 180

degrees

Area of minor segment =

(Area of sector) – (Area of triangle)

Area of minor segment =

(Area of sector) – (Area of triangle)

12 yd

2 1

*360 2

mRQr b h

R

Q290 1

(12) (12)*(12)360 2

113.10 72

241.10yd

CW/ HW

• Book page 226 #8-10, 17-21

• Book page 232 #10-15, 22, 23, 29