1 / 20

Sectors of Circles - Finding Arc Length and Area

This lesson focuses on finding the arc length and area of a sector of a circle, as well as solving problems involving apparent size. It covers the formulas and variables involved in working with sectors of circles, and provides examples and practice problems.

fgarrity
Download Presentation

Sectors of Circles - Finding Arc Length and Area

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. Lesson 7-2 Sectors of Circles

  2. Objective:

  3. Objective: To find the arc length and area of a sector of a circle and to solve problems involving apparent size.

  4. A sector of a circle is the piece of pizza/pie that is cut out of a circular pizza/pie.

  5. Suppose we have a sectorlike the one shown: 12 s 60°

  6. Suppose we have a sectorlike the one shown: When working with formulas involving sectors; r, s andθare the variables involved. θ must always be in terms of radians to be used appropriately. 12 s 60°

  7. Suppose we have a sectorlike the one shown: Therefore, before you attempt to find s, r, or the area of a sector; first convert θ to radian measure if it is not already done so. 12 s 60°

  8. To change a degree measure to a radian measure, multiply by

  9. To change a degree measure to a radian measure, multiply by

  10. So, if the angle measure given is 600; we first convert by multiplying

  11. So, if the angle measure given is 600; we first convert by multiplying

  12. Now to find the area of a sector, we can simply use the formula:

  13. Now to find the area of a sector, we can simply use the formula:

  14. A sector of a circle has arc length 6 cm and area 75 cm2. Find its radius and the measure of its central angle.

  15. When there is nothing in our field of vision against which to judge the size of an object, we perceive the object to be smaller when it is farther away. For example, the sun is much larger than the moon, but we perceive the sun to be about the same size as the moon because the sun is so much farther from Earth.

  16. So, how big an object looks depends not only on its size but also on the angle that it subtends at our eyes.

  17. So, how big an object looks depends not only on its size but also on the angle that it subtends at our eyes. The measure of this angle is called the object’s apparent size.

  18. Jupiter has an apparent size of 0.01° when it is 8 x 108 km from Earth. Find the approximate diameter of Jupiter.

  19. A sector has perimeter 16 cm and area 15 cm2. Find its radius r and arc length s.

  20. Assignment:Pg. 265 C.E. 1-4 allW.E. 1-15 odd

More Related