However, the triangles are given to me unordered (it is out of an STL file), so my derived line segments are also unordered.<BR><BR>My current algorithm for linking these segments together back ...

Or a triangle ... same value in the case of a unit circle!) This is why the square does not trace a straight diagonal line, as you might expect, but a segment of the tangent function.

Save guides, add subjects and pick up where you left off with your BBC account. Calculate the missing angles \(x\), \(y\) and \(z\). The angle in a semicircle is 90°.