Step Instructions[br]1 Create [b]Slider a[/b] from 0 to 2 π (enter 2 π by typing 2 pi)[br][color=#1551b5]2 Type [b]Origin = (0,0)[/b] into Input.[/color][br]3 Type [b](a, 0)[/b][br]4 Type [b]C = (a, 1)[/b][br][color=#1551b5]5 Type [b]Circle[C,1][/b][/color][br][color=#c51414]6 [b]Segment[Origin,A][/b], draw or type command, [br] a) change color (red), heavy line; SetColor[ c, "Red" ], SetLineThickness[ c, 8 ][/color][br]7 [b]Rotate Object around Point by Angle[/b]: click on Point A then C rotated by angle (type) 2 π - a[br][color=#c51414]8 [b]CircularArc center between two points [/b]click on the points in this order [C, A, A'], [br] a) change arc color (red), heavy line to match #6; SetColor[ c, "Red" ], SetLineThickness[ c, 8 ].[/color]