1. 5 6 9 360° 360° 360° 360° 360° Angles in polygons 3 x 180 = 540°
1. Use the rules to complete the following table:
Polygon
Sides
Sum of exterior angles
Sum of interior angles
For regular polygon
Exterior angle
Interior angle
Pentagon
Hexagon
Nonagon
Decagon 10
Pendedecagon 15 5
360°
3 x 180 = 540°
𝟑𝟔𝟎° 𝟓 =𝟕𝟐°
𝟓𝟒𝟎° 𝟓 =𝟏𝟎𝟖° 6
360°
4 x 180 = 720°
𝟑𝟔𝟎° 𝟔 =𝟔𝟎°
𝟕𝟐𝟎° 𝟔 =𝟏𝟐𝟎° 9
360°
7 x 180 = 1260°
𝟑𝟔𝟎° 𝟗 =𝟒𝟎°
𝟏𝟐𝟔𝟎° 𝟗 =𝟏𝟒𝟎°
360°
8 x 180 = 1440°
𝟑𝟔𝟎° 𝟏𝟎 =𝟑𝟔°
𝟏𝟒𝟒𝟎° 𝟏𝟎 =𝟏𝟒𝟒°
360°
13 x 180 = 2340°
𝟑𝟔𝟎° 𝟏𝟓 =𝟐𝟒°
𝟐𝟑𝟒𝟎° 𝟏𝟓 =𝟏𝟓𝟔°

2. Sum of exterior angles = 360°
1. Dave says “There is a regular polygon with exterior angles of 50°” Show why Dave is wrong
Sum of exterior angles = 360°
Let 𝒏 be the number of sides
50 x 𝒏 = 360°??
𝒏 = 360° ÷ 50 = 7.2
2. John says “There is a regular polygon with interior angles of 170°”. Show why John is correct
Interior angle + Exterior angle = 180°
170° + Exterior angle = 180°
Exterior angle = 10°
10 x 𝒏 = 360°??
𝒏 = 360° ÷ 10 = 36

3. Homework for Monday: Mixed Exercise
Pg 132 – 133 Exercise 6h No. 1 to No. 6