In this unit we will learn how to construct and 'define' star-shaped polygons. The first part involves a description of how to construct them, using a ruler and compass, although we will be using the computer to draw them. The second part is somewhat more abstract as we discover which conditions we need to produce a star-shaped polygon and which properties it has. In both parts we use algorithms to give constructive explanations, i.e. we define star-shaped polygons as shapes obtained by follo...