ppt for.classroom observation topic Area of sector of a Circle

1. MATHEMATICS 10
SECTOR OF A CIRCLE

2. ACROSS
3. The secondary sector relies on manufacturing and
construction.
DOWN
1. The primary sector is the part of the economy focused on
extracting natural resources from the environment.
2. The tertiary sector responds to the needs and desires of
consumers by providing services.
Criss Cross puzzle of Economic Sectors

3. ACROSS
3. The secondary sector relies on manufacturing and
construction.
DOWN
1. The primary sector is the part of the economy
focused on extracting natural resources from the
environment.
2. The tertiary sector responds to the needs and
desires of consumers by providing services.
A
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A
L
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I N D U S R A L
Criss Cross puzzle of Economic Sectors

4. • ASIDE ECONOMIC
SECTOR, WE ALSO HAVE
COMMUNITY SECTOR
SPECIALLY IN OUR
BARANGAY/
MUNICIPALITY, WHO CAN
GIVE ME A SECTORAL
GROUP IN OUR

5. FOR YOU, WHAT IS A
SECTOR?

6. GDP- Gross Domestic Product measures the
monetary value of final goods and services that is,
those that are brought by the final user – produced
in a country in a given period of time.

7. Activity: By group
Instructions:
This is a group activity related to the GDP 2022 of
Economic sector and must be done within 5
minutes. Each group will select their LMNOP
(L – Leader, M – Materials in Charge,N- Note Taker,
O- Observer and P - Presentor )

8. 8.90%
29.70%
61.40%
Philippine GDP by Sector
2022
Agriculture Industrial
Service
The Circle graph shows
the Philippines GDP by
Sector 2022. Find the
measure of the central
angle of the sector that
shows the biggest share
of the Philippines GDP.
1. Read the problem
2. Identify the percentage of the
sector
3. Change the percent to a
decimal
4. Multiply the decimal by 360𝑜
Activity: By group
Questions:
1. What is the percentage of each economic sector?
2. What sector has the smallest share on the GDP?
3. What is the central angle of the biggest hare in the
Philipines GDP 2022?
4. How did you calculate the Central Angle?

9. 8.90%
29.70%
61.40%
Philippine GDP by Sector
2022
Agriculture Industrial
Service
The Circle graph shows
the Philippines GDP by
Sector 2022. Find the
measure of the central
angle of the sector that
shows the biggest share
of the Philippines GDP.
Activity: By group
Questions:
1. What is the percentage of each economic sector?
2. What sector has the smallest share on the GDP?
3. What is the central angle of the biggest share in
the Philipines GDP 2022?
4. How did you calculate the Central Angle?
Agriculture 8.90%, Industrial 29.70%, Service
61.40% Agricultur
e
221.04 degrees
By Multiplying the percentage
and 360 degrees

10. 1.Determine the central angle and radius
of a circle.
2. Find the area of the sector of a circle; and
3. Demonstrate appreciation in the application
of sector of a circle in real life.
Learning Objectives:

11. A sector of a circle is the region bounded by an
arc of the circle and the two radii to the
endpoints of the arc.
Sector of a Circle:

18. Area of a Sector of a Circle:
To find the area of a sector of a circle,
get the product of the
measure of the arc
3600 and the area of the circle.
Area of sector = measure of the arc
3600 πr2

19. Area of a Sector of a Circle:
Example: The radius of circle C is 10 cm. If the measure of
arc 𝐴𝐵= 60 ,what is the area of sector ACB?
Solution:
To find the area of sector ACB
Area of sector ACB = (
measure of the arc
3600 )(Area of the circle)
Area of sector ACB = (
measure of the arc
3600 )πr2
Area of sector ACB = (
60
3600 ) π (10 cm)2
= (
1
6 ) π (100cm2)
=
100
6 π cm2
=
50
3
π cm2
The area of sector ACB is
50
π cm2

20. Area of a Sector of a Circle:
Practice:
A slice of pizza
has a radius of 9
inches. It Forms an
angle of 30o at the
center. Find the
area of the slice

21. Area of a Sector of a Circle:
Practice:
A slice of pizza
has a radius of 9
inches. It Forms an
angle of 30o at the
center. Find the
area of the slice
Answer: 27/4 𝜋 𝑠𝑞𝑢𝑎𝑟𝑒 𝑖𝑛𝑐ℎ 𝑜𝑟
6.75𝜋 𝑠𝑞𝑢𝑎𝑟𝑒 𝑖𝑛𝑐ℎ

22. Area of a Sector of a Circle:
Practice:
A bad sector is a sector of a
computer or external hard drive,
Compact Disc, SD memory card, USB
flash drive, or pen drive that is
neither accessible nor writeable.
Given the figure on the left, A
Compact Disc has a diameter of 12
cm and 1/3 of the CD is the bad
sector. Determine the central angle of
the bad sector and solve the area of
the bad sector

23. Area of a Sector of a Circle:
Practice:
A bad sector is a sector of a
computer or external hard drive,
Compact Disc, SD memory card, USB
flash drive, or pen drive that is
neither accessible nor writeable.
Given the figure on the left, A
Compact Disc has a diameter of 12
cm and 1/3 of the CD is the bad
sector. Determine the central angle of
the bad sector and solve the area of
the bad sector
Answer: Centra angle of the bad sector is 1200
Area of the bad sector is 48 𝜋 𝑐𝑚2

24. Finding Application of Area of a Sector of a Circle:
In what field of work does sector of a
circle commonly use or applies best?

25. Generalization:
What is a sector of a circle?

26. Generalization:
Part 1
“ Maricar was baking a pizza pie with a
diameter of 12 inches. She divided it into six equal
parts and eats one slice .”
1. What is the radius of the pizza pie? 1pt
a. 12 cm b. 12inches c. 6 cm d. 6 inches
2. What is the degree measure of each slices? 1pt
a. 30o a. 45o a. 60o a. 90o
Part 2 (3 pts)
A pizza with 21 cm radius is divided into 6
equal slices (slices are in the shape of a
sector). Solve for the area of each slice.

27. Generalization:
Part 2: 3 pts
A pizza with 21 cm radius is divided into 6
equal slices (slices are in the shape of a
sector). Solve for the area of each slice.
3 2 1
Used an
appropriate
strategy to come
up with the
correct solution
and arrived at a
correct answer for
Used an
appropriate
strategy to
come up with a
solution, but a
part of the
solution led to
Attempted to
solve the
problem but used
an inappropriate
strategy that led
to an wrong
solution..
Rubrics for solving