Demiregular Tessellation 1

Move point A and point B to explore the tessellation. This is a Java Applet created using GeoGebra from www.geogebra.org - it looks like you don't have Java installed, please go to www.java.com There is no clear definition of what demi-regular tessellations are. Some sources say that there are 14 of them, but give different types. Some also say that there are 20 of them.