1. Y8 Polygon Workbook

2. Investigation: What is the sum of interior angles of a 100 sided shape?
Name of Polygon
Number of sides for the polygon
Number of triangles inside the polygon
Sum of interior angles for the polygon
Size of one interior angle
Triangle
Quadrilateral
Pentagon
Hexagon
Heptagon
Octagon
Nonagon
Decagon
any-sided polygon

3. Interior angles of polygons
This is just one of the six interior angles of this polygon

4. The angle sum of a triangle is 180°
A polygon with 3 sides is a triangle 𝒃 â ĉ
The angle sum of a triangle is 180°
𝑎 + 𝑏 + 𝑐 = 180°

5. What is the angle sum of a quadrilateral?
triangle
= 180°
Angle sum of a triangle = 180°
The angle sum of a quadrilateral is 360°

6. Here is a different quadrilateral but the method is the same
Angle sum of
a triangle = 180°
Angle sum of
a triangle = 180°
The angle sum of a quadrilateral is 360°

7. What is the angle sum of a pentagon?
180°x 3 = 540°
This time you can divide the polygon into 3 triangles
The angle sum of a pentagon is 540°

8. You can find the angle sum of any polygon by dividing it up into triangles
180° x 4 = 720°
180° x 5 = 900°
180° x 6 = 1080°

9. What is the formula for finding the angle sum of a dodecagon
Finding a formula
What is the formula for finding the angle sum of a dodecagon
(a 12-sided polygon)?