角度のパズル - DyGeom.m on Mathematica+KETpic

SetDirectory[NotebookDirectory[]];
<< DyGeom.m
p1 = FreePoint[{0, 0}, pointname -> "A", pointposition -> "w"]
p2 = FreePoint[{4, 0}, pointname -> "B", pointposition -> "e"]
l1 = ConnectPoints[p1, p2, clipping -> {p1, p2}]
l2 = N[AngleLine[l1, p1, 50]]
l3 = AngleLine[l1, p1, 80]
l4 = AngleLine[l1, p2, -60]
l5 = AngleLine[l1, p2, -80]
p3 = IntersectionLL[l2, l5]
p4 = IntersectionLL[l3, l4]
l6 = ConnectPoints[p3, p4]
l2 = AddOption[l2, clipping -> {p1, p3}]
l3 = AddOption[l3, clipping -> {p1, p4}]
l4 = AddOption[l4, clipping -> {p2, p4}]
l5 = AddOption[l5, clipping -> {p2, p3}]
l6 = AddOption[l6, clipping -> {p3, p4}]
m1 = AngleMarkBy3[p2, p1, p3, markname -> "50", markposition -> 0.8]
m2 = AngleMarkBy3[p3, p1, p4, markname -> "30", markposition -> 1.0]
m3 = AngleMarkBy3[p4, p2, p1, markname -> "60", markposition -> 0.8]
m4 = AngleMarkBy3[p3, p2, p4, markname -> "20", markposition -> 1.1]
m5 = AngleMarkBy3[p2, p4, p3, markname -> "?", markposition -> 0.8]
DrawConstruction[{p1, p2, l1, l2, l3, l4, l5, p3, p4, l6, m1, m2, m3, m4, m5}]

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