http://www.ck12.org Chapter 1. Basics of Geometry
Example 10:Name the three polygons below by their number of sides and if it is convex or concave.
Solution:
A. This shape has six sides and concave, so it is a concave hexagon.
B. This shape has five sides and is convex, so it is a convex pentagon.
C. This shape has ten sides and is convex, so it is a convex decagon.
Know What? RevisitedThe pentagon is divided up into 10 sections, all quadrilaterals. More specifically, there are
5 rectangles and 5 kites. None of these dividing lines are diagonals because they are not drawn from vertices.
Review Questions
For questions 1-6, classify each triangle by its sides and by its angles.