10.7 area of circles + sectors.notebook
March 20, 2017
3/20/17 - Warm Up Problem
Find the measure of each arc.
A
1. Arc AD =
2. Arc ADC =
3. ArcAC =
B
48
o
E
4. Arc BCA =
C
D
10.7 area of circles + sectors.notebook
The largest
circular pizza ever
baked was in 1990
in South Africa.
It's diameter was
123 feet. How
many square feet
of pizza did they
have to give away?
March 20, 2017
10.7 area of circles + sectors.notebook
March 20, 2017
Section 10.7 - Area of Circles and Sectors
Goal: Calculate the area of circles, sectors, and segments of
circles
How could we adapt this formula to work for circles?
A=
1
Pa
2
Area of a Circle
Calculate the area in terms of pi of each circle.
in
22 cm
12
8 ft
10.7 area of circles + sectors.notebook
How much more pizza is in a 12 in diameter pizza
than a 10 in diameter pizza?
March 20, 2017
10.7 area of circles + sectors.notebook
March 20, 2017
The Jacobson's tie their goat to the corner of a 4-meter by
5-meter shed. The goat's chain is 3 meters long and is
attached to the shed at ground level. What is the area of
grass that the goat can reach?
4m
3m
5m
10.7 area of circles + sectors.notebook
March 20, 2017
Sectors
B
Sector XOY
C
Area of a Sector
m
2
A = πr 360
radius
Sector BCA
A
sector's arc measure
(in degrees)
tells how much of the circle you are finding the area of
10.7 area of circles + sectors.notebook
March 20, 2017
Find the area of the pink shaded sector in terms of pi.
2
A = πr
m
360
10.7 area of circles + sectors.notebook
Segment of a Circle
part of a circle formed by an
arc and the segment joining
its endpoints
Area of a Segment
Find the shaded area.
March 20, 2017
10.7 area of circles + sectors.notebook
Assignment:
pg. 663
(7-18)
(23-25)
March 20, 2017