It contains, among other things, sections on similarity, transversals, vector geometry, inversion, and coaxal circles ... A Course of Plane Geometry for Advanced Students. Part 1.

we need to know what fraction of the circle is shown. To do this, we use the angle and compare it with 360˚. This angle is 144°. That is \(\frac{{144^\circ }}{{360^\circ }} = \frac{2}{ ...

With all that​ emphasis on the significance of the square in our lives, how did we get to that semi-put down of the middle of the last century “Be there or be square”?