Everyone knows that triangles have 3 sides but what the shirt in our fall curiosity box presupposes is, what if they don’t? The mid point of each of a triangle’s sides, the foot of each of its altitudes and the midpoint between its orthocentre and each of its vertices all fall on the circumference of a circle. A triangles in-circle is the largest circle that fits inside it, and its circumcircle is the circle in which all of its vertices lie. Now relative to these three circles, the sides can be described. They each have endpoints on the circumcircle, mid points on the 9 point circle, and are tangent to the in-circle, but in 1993, B.F.Sherman discovered that there are not three lines with these properties, there are four. And our shirt celebrates it. This orange line is the fourth side of this triangle.