Circles: Arc Length and Sector Area

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Presentation transcript:

Circles: Arc Length and Sector Area 9.3.3.8 Know and apply properties of a circle to solve problems and logically justify results.

Guiding Question: How can I find part of a circumference or part of a circle? Lesson Obj: IWBAT find an arc length or sector area of a circle. Recall Circles Definition of a circle Radius Diameter Circumference Area

Guiding Question: How can I find part of a circumference or part of a circle? Parts of a circle How do you calculate circumference? What if I only wanted part of that?

Guiding Question: How can I find part of a circumference or part of a circle?

Guiding Question: How can I find part of a circumference or part of a circle? To solve divide the angle by 360 and multiply by the circumference. Calculate the arc length of this circle.

Guiding Question: How can I find part of a circumference or part of a circle? Arc Length Sector Area Finding part of the circumference Never looking inside the circle No area only length (label is not squared) Finding part of the area of a circle Only looking inside the circle Answer is an area, should be squared

Guiding Question: How can I find part of a circumference or part of a circle? For an arc = 𝜃 360 2𝜋𝑟 For a sector area = 𝜃 360 𝜋 𝑟 2

Find the sector area in this problem Guiding Question: How can I find part of a circumference or part of a circle? Find the sector area in this problem Find the area here.

Guiding Question: How can I find part of a circumference or part of a circle? Assignment: Arc length and Sector Area packet