Circular Arc Segments: TextPaths & Transformations

This example shows how arc paths can create segments of circles(The arc's x,y radius are set equal). It includes a textPath and start/end arrows. After an arc is transformed, via translate and/or rotation, the transforms can be removed and screen X,Y values can be computed. Arrow markers are designed to align relative to path curvature.
Text along circle segment

 TextPath:  Start Arrow:  End Arrow:

Semi-Circles: Absolute Value(Start Angle +/- End Angle) = 180 degrees

Cx:   Cy:  Rxy:   Start Angle:  End Angle:  

x:  y:     Angle:   

Arc path d format: d = "M startX,startY A rx, ry, x-axis-rotation, large-arc-flag, sweep-flag, endX, endY"
SVG Source:
Javascript: