Exploring Pi with Trigonometry

Trigonometry that seems to have nothing to do with circles or anything having no angles does work in measuring tangent pi on angles on triangles with an area equal to or twice as large as that of a circle and having angles with pi or 2*pi in tangent.

pi-tan(72.343212845degrees) - Google Search -

My Excel sheets show how calculation was made and the relevant trigonometric function.

Excel Trigonometry