1 / 9

11.4 Circumference and Arc Length

11.4 Circumference and Arc Length . Learning Target: I can use similarity to calculate the length of an arc. . **. Review:. Interior angles of a polygon Find the sum of the measures of the interior angles of a convex 20-gon. Sum of interior angles = (n – 2) · 180°

chadrick
Download Presentation

11.4 Circumference and Arc Length

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. 11.4 Circumference and Arc Length Learning Target: I can use similarity to calculate the length of an arc.

  2. ** Review: Interior angles of a polygon • Find the sum of the measures of the interior angles of a convex 20-gon. Sum of interior angles = (n – 2) · 180° = (20 – 2) · 180° = (18) · 180° = 3240°

  3. Circumference of a Circle • The circumference ( C ) of a circle is • C = πd or • C = 2πr where d = diameter of the circle and r = radius of the circle.

  4. ** Example: (a) Find the circumference of a circle with radius 6cm (b)Find the radius of a circle with circumference 31m. Circumference = 2πr C = 2π(6) C=12π Circumference = 2πr 31 = 2πr r ≈ 4.9

  5. Arc Length Corollary In a circle, the ratio of the length of a given arc to the circumference is equal to the ratio of the measure of the arc to 360°. Arc length of AB =

  6. . C A 50° 5 . 7 50° D B Find the length of each arc.

  7. Find mPR

  8. P . 3.82 60° Q R Find the circumference. Circumference = 2πr

  9. Find the circumference. Circumference = 2πr

More Related