外心と外接円 - DyGeom.m on Mathematica+KETpic

<< DyGeom.m
p1 = FreePoint[-4, -1, pointname -> "A", pointposition -> "sw"]
p2 = FreePoint[1, 4, pointname -> "B", pointposition -> "ne"]
p3 = FreePoint[2, -1, pointname -> "C", pointposition -> "se"]
l1 = ConnectPoints[p1, p2, clipping -> {p1, p2}]
l2 = ConnectPoints[p2, p3, clipping -> {p2, p3}]
l3 = ConnectPoints[p3, p1, clipping -> {p3, p1}]
p4 = MidPoint[p1, p2]
l4 = PerpendicularLine[p4, l1]
p5 = MidPoint[p2, p3]
l5 = PerpendicularLine[p5, l2]
p7 = IntersectionLL[l4, l5,pointname->"O",pointposition->"e"]
c1 = CircleByCenter[p7, p1]
DrawConstruction[p1, p2, p3, l1, l2, l3, p7, c1]

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