1 / 13

POLYGONS

POLYGONS. A polygon is a shape enclosed by straight lines. TRIANGLE. QUADRILATERAL. sum of interior angles . sum of interior angles = 180°. = 2 x 180 ° = 360 °. PENTAGON. HEXAGON. sum of interior angles . sum of interior angles . = 4 x 180 ° = 720 °. = 3 x 180 ° = 540 °.

mirari
Télécharger la présentation

POLYGONS

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. POLYGONS

  2. A polygon is a shape enclosed by straight lines.

  3. TRIANGLE QUADRILATERAL sum of interior angles sum of interior angles = 180° = 2 x 180° = 360° PENTAGON HEXAGON sum of interior angles sum of interior angles = 4 x 180° = 720° = 3 x 180°= 540°

  4. An n-sided polygon can be split into (n– 2) triangles. The sum of the interior angles in an n-sided polygon = (n– 2) x 180° Example Find the sum of the interior angles in a nonagon. Sum of interior angles = (n– 2) x 180° = (9 – 2) x 180° = 7 x 180° = 1260°

  5. x 140° 107° 75° 105° Example Find the value of x. Sum of interior angles = (5 – 2) x 180° = 540° x + 75 + 105 + 107 + 140 = 540 x + 427 = 540 x = 113°

  6. In a regular polygon • All the sides are the same length AND • All the angles are the same size

  7. Regular or not?        

  8. EXTERIORANGLE INTERIORANGLE

  9. Regular hexagon Sum of exterior angles = 360° 60° 120° Exterior angle = 360° ÷ 6 = 60° Interior angle = 180° – 60° = 120°

  10. Regular pentagon Sum of exterior angles = 360° 108° 72° Exterior angle = 360° ÷ 5 = 7° Interior angle = 180° – 72° = 108°

  11. Regular octagon Sum of exterior angles = 360° 45° 135° Exterior angle = 360° ÷ 8 = 45° Interior angle = 180° – 45° = 135°

  12. Exterior angle = Interior angle = In a regular n-sided polygon: Example The interior angle of a regular polygon is 156°. How many sides does the polygon have? Interior angle = The polygon has 15 sides.

  13. F E D x C A B Example ABCDE is a regular pentagon. Find the size of angle x . 72° 72° Angle AEF = exterior angle = 360 ÷ 5 = 72° Angle EAF = 72° x = 180 – (72 + 72) = 36°

More Related