L6.1 Polygon Interior Angle Sum

Explore Convex Polygon Angles' Measure Sum

Use this applet to study patterns with interior angle sums of polygons.

Explore Concave Polygon Angles' Measure Sum

 Since one of the angles forces the polygon to be CONCAVE, does it affect the polygon angle sum?

Draw in the auxiliary segments: diagonals.

Draw in the auxiliary segments: diagonals.

How many diagonals are there from the vertex E in the quadrilateral? How many diagonals are there from the vertex D in the quadrilateral? Did the amount change? How many triangles are formed by the diagonals?

How many diagonals are there from the vertex H the pentagon? How many diagonals are there from the vertex L the pentagon? Did the amount change? How many triangles are formed by the diagonals?