arc length and sector area

Arc Length and Sector Area7-7 and 7-8

Notecard Warm Up – To be Turned In› Write your name on the notecard› On the provided notecard, write the

formula for the area of the following (NO PICTURES):– Rectangle– Triangle– Square– Trapezoid– Parallelogram– Regular Polygon– Rhombus– Kite

Homework Check1. 172.8in2 2. 144in2 3. 5544m24. 12933.6m2 5. 525m2 6.

85cm27. 259.8in2 8. 946.4cm29. <1=120, <2=60, <3=3010. <4=90, <5=45, <6=4511. <7=60, <8=30, <9=6012. <1=36, <2=18, <3=72

Extra Practice1. 200cm2 2. 525in23. 432m2 4. 33.8cm25. 216in2 6. 1167. 482.84 8. 1039.23cm29. 133m2 10. 672in211. 80in2 12. 120in213. 415 14. 36cm2

Quiz› 20 Minutes› You may use notecard

Today’s Objective› Students will be able to calculate the length of an arc and the area of a sector.

7-6 Arc Length› Review: The Circumference is the

distance around a circle. – C=2πr or C=πd

› Definition: The Arc Length is the distance around an arc (a fraction of the circumference)

› Arc length is DIFFERENT from Arc Measure****

Arc Length: is a fraction of a circle’s circumference (in terms of pi)

Arc Measure: is equal to the central angle (in terms of degrees)

Example› Find the LENGTH of arc AB

Ex 2: Find the length of arc ADB

7-7 Sector Area› Review: The Area of a circle is π*r2

› Definition: A Sector is a region bounded by an arc and two radii

Segment of a CircleDefinition: A part of a circle bounded

by an arc and the segment joining its endpoints

Area of a Segment

Finding the Area of a Segment of a CircleEx 1: Find the area of the segment:

Example: Find the area of the shaded region

Challenge Find the area of the green figure.

Classwork/Homework› Page 7 of Packet

– 9. 90 10. 36 11. 45 12. 90+45 15. d=8

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