1 / 17

CIRCLES 2

CIRCLES 2. radius. circumference. centre. tangent. diameter. chord. area of circle. Area of red square. ‹. ‹. A. 4r 2. Area of blue square. area of circle. ‹. ‹. A. 2r 2. Let’s look at the area inside a circle. Let’s use a diagram to help. ‹. c. ‹. 6r. 8r.

pparks
Download Presentation

CIRCLES 2

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. CIRCLES 2

  2. radius circumference centre tangent diameter chord

  3. area of circle Area of red square ‹ ‹ A 4r2

  4. Area of blue square area of circle ‹ ‹ A 2r2

  5. Let’s look at the area inside a circle

  6. Let’s use a diagram to help ‹ c ‹ 6r 8r Explain why the statement must be true

  7. A group of students measured the radius & estimated the area of five circles to see how they were related. Here are their results

  8. The equation of the curve is A = 3.1r2 Here is their graph

  9. π xd C = πd C =2πr 2x π xr A =πr2 π xr xr

  10. This circle has a diameter of 20 cm. Find the radius, circumference & area of the circle 20 cm Useπ= 3.14

  11. d2 Radius = 20 cm 20 2 = = 10 cm πd circumference = π x 20 = = 3.14 x 20 = 62.8 cm πr2 area = 3.14 x 10 x 10 = = 314 cm2

  12. Choose a problem semicircle sector End

  13. Calculate the perimeter and area of this semicircle Useπ= 3.14 12 m

  14. Calculate the perimeter and area of this semicircle Useπ= 3.14 12 m πr22 πd2 Perimeter = + d Area = = 3.14 x 12 x 6 = (3.14 x 12) + 24 = 37.68 + 24 = 3.14 x 12 x 6 = 61.68 m = 226.08 m2

  15. Calculate the perimeter and area of this sector 8 cm Useπ= 3.14 60o

  16. Calculate the perimeter and area of this sector 8 cm Useπ= 3.14 60o πr2 6 πd6 Perimeter = + 2r Area = = 3.14 x 8 x 8 6 = (3.14 x 16) + 16 6 = 24.4 cm = 34.5 cm2

  17. End

More Related