Finding the Sum of a Polygons Interior Angles
- Slides: 10
Finding the Sum of a Polygon’s Interior Angles Here are some polygons 13 -Jun-21 The word ‘polygon’ is a Greek word. Poly means many and gon Triangle Pentagon Octagon means angles.
How to find the sum of the interior angles – i. e. How to find a + b + c + d + e b a c e d
How to find the sum of the interior angles – i. e. How to find a + b + c + d + e Split the shape up into triangles
How to find the sum of the interior angles – i. e. How to find a + b + c + d + e Split the shape up into triangles 1800 Each triangle contains 1800
How to find the sum of the interior angles – i. e. How to find a + b + c + d + e Split the shape up into triangles 1800 Each triangle contains 1800 3 x 180 = 5400 1800
How to find the sum of the interior angles – i. e. How to find a + b + c + d + e Split the shape up into triangles 1800 Each triangle contains 1800 3 x 180 = 5400 1800 The sum of the interior angles is 5400
Copy and complete this table. Find the interior angles by drawing and splitting up into triangles. Name Number Sum of Interior Angles of Sides Quadrilateral 4 Pentagon 5 Hexagon 6 Heptagon 7 Octagon 8 Nonagon 9 Decagon 10
Copy and complete this table. Find the interior angles by drawing and splitting up into triangles. Name Number Sum of Interior Angles of Sides Quadrilateral 4 360 Pentagon 5 540 Hexagon 6 720 Heptagon 7 900 Octagon 8 1080 Nonagon 9 1260 Decagon 10 1440
Regular Polygons NB. If the polygon is regular, to find an interior angle use the rule: Interior Angle 1200 Int. Angle = 180 – (360 ÷ n) n is the number of sides Int. = 180 – (360 ÷ 6) 180 – 60 =120
Regular Polygons NB. If the polygon is regular, to find an exterior angle use the rule: exterior angle (180 – 120 = 60 Interior Angle 1200 Ext. Angle = 360 ÷ n n is the number of sides And Ext. Angle = 180 – Int. Angle
