Windows come in many shapes and sizes. Some commonly used shapes for windows are circles, rectangles, squares, triangles, pentagons, and octagons. Source: www.pella.com One of those amazingly horrible attempts at making something “real world” in a textbook. This is a high school math textbook. The source for this staggering information is a website that sells windows. And they double down on their insistence that windows make this content relevant and useful to today’d hip teens by using windows in two examples. Remember aspiring teen window makers, you can use the reflective property of congruence in your future job interview!