St. Patrick's Day front/back T-Shirt

Happy St. Patrick's Day to all you math geeks and geometry teachers! This design features shamrock geometry on the front of the tee and the text "Happy St. Patrick's Day!" on the back. Choose from men's, women's or children's styles in many shades of green. the shamrock shows the equation for the area of a circle, diagrams of the circumference, diameter, radius, sector, arc and chord for circles, plus a few other things. For the truly curious: the small center circle shows that the angle in a semicircle is always a right angle; the bottom ellipse on the shamrock's stem illustrates how to find the axes of an ellipse; and the 2 smaller ellipses in the stem illustrate how to find the foci of an ellipse. Enjoy!