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11.5 Areas of Circles and Sectors. CA State Standards. Lesson Goals. Find the area o f a sector. 8 : Solve problems involving perimeter and area. 19: Use trigonometric functions 21. Prove and solve problems regarding circle parts. ESLRs: Becoming Effective Communicators,
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11.5 Areas of Circles and Sectors CA State Standards Lesson Goals Find the area of a sector. • 8: Solve problems involving perimeter andarea. • 19: Use trigonometric functions • 21. Prove and solve problems regarding circle parts. ESLRs: Becoming Effective Communicators, Competent Learners and Complex Thinkers
theorem Area of a Circle: Area of a circle is still measured in square units. r
definition Sector of a Circle The region bounded by two radii and their intercepted arc. (like a piece of pie) r
Theorem Area of a Sector The ratio of the area A of a sector of a circle to the area of the circle is equal to the ratio of the measure of the intercepted arc to 360°. or A B C
example Find the area of the circle 3m
example Find the area of the circle 18ft
example Find the area of the sector Y Z 135o 11 m X
example Find the area of the sector L 150o M R 50 cm N
Today’s Assignment p. 695: 3 – 9, 17, 18, 21, 22, 33