1 / 22

7.7 Areas of Circles and Sectors

7.7 Areas of Circles and Sectors. Quick Review. What is the circumference of a circle?. What is the area of a circle?. The interior angle sum of a circle is ?. What is the arc length formula?. Sector of a Circle. Formula is very similar to arc length

Download Presentation

7.7 Areas of Circles and Sectors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. 7.7 Areas of Circles and Sectors

  2. Quick Review • What is the circumference of a circle? • What is the area of a circle? • The interior angle sum of a circle is ? • What is the arc length formula?

  3. Sector of a Circle • Formula is very similar to arc length • Notation is slightly different! - The center pt is used when describing a sector. - The is not used for sectors.

  4. How can we find area, based on what we already know?

  5. Area of a sector =

  6. 1. Find the area of the shaded sector2. Find the arc length of the shaded sector.

  7. Segmentany ideas of how to find the shaded area?

  8. Finding the Area of a Segment of a Circle – = Area of Sector Area of Triangle Area of Segment minus equals

  9. Find the area of segment RST to the nearest hundredth. Step 1 Find the area of sector RST. Use formula for area of sector. Substitute 4 for r and 90 for m. = 4π m2

  10. Continued Find the area of segment RST to the nearest hundredth. Step 2 Find the area of ∆RST. ST = 4 m, and RS = 4m. = 8 m2 Simplify.

  11. Continued Find the area of segment RST to the nearest hundredth. Step 3 area of segment = area of sector RST – area of ∆RST = 4π – 8  4.57 m2

  12. A segment of a circle

  13. Finding the Area of a Segment Find the area of segment LNM to the nearest hundredth. Step 1 Find the area of sector LNM. Use formula for area of sector. Substitute 9 for r and 120 for m. = 27π cm2

  14. Step 2 Find the area of ∆LNM. Draw altitude NO. Continued Find the area of segment LNM to the nearest hundredth.

  15. Continued Find the area of segment LNM to the nearest hundredth. Step 3 area of segment = area of sector LNM – area of ∆LNM = 49.75 cm2

  16. Find the area of the shaded portion

  17. Find the area of the red portion Of the Tube Sign.

  18. Find the shaded area with r = 2 , 4 , & 10

  19. What is the Area of the Black part? 3cm 1cm 5cm

  20. If you have 2 circles A and B that intersect at 2 points and the distance between the centers is 10. What is the area of the intersecting region? A B 10

  21. Classwork Time - Go! Page 397 7 - 27 odd 31-33 36-38

More Related