费尔巴赫定理与费尔巴赫点
几何画板及绘图内容加载中,请稍等……
该范例演示了费尔巴赫定理,即九点圆内切于内切圆且外切于三个旁切圆。通过使用GeoGebra命令如Line, OrthogonalLine, LineBisector等,可以构造出九点圆、内切圆和旁切圆,并观察它们之间的关系。适合初中及以上学生学习几何作图和圆的相关性质。
GeoGebra 命令及参数
Line(A, B) → mLine(C, A) → nLine(B, C) → qOrthogonalLine(A, q) → aOrthogonalLine(B, n) → bOrthogonalLine(C, m) → cLineBisector(B, C) → dLineBisector(C, A) → eLineBisector(A, B) → fIntersect(q, a) → DIntersect(n, e) → EIntersect(n, b) → F_1Intersect(m, c) → G_1Intersect(m, f) → IIntersect(q, d) → JCircle(G_1, D, E) → kSegment(A, J) → iSegment(B, E) → jSegment(I, C) → lIntersect(i, j) → GAngularBisector(n, m) → g, hAngularBisector(q, m) → p, rAngularBisector(n, q) → s, tIntersect(g, p) → HIntersect(h, r) → KIntersect(h, p) → LIntersect(g, r) → MOrthogonalLine(M, q) → a_1OrthogonalLine(L, q) → b_1OrthogonalLine(H, n) → c_1Intersect(n, c_1) → NCircle(H, N) → d_1Intersect(q, a_1) → OCircle(M, O) → e_1Intersect(q, b_1) → PCircle(L, P) → f_1OrthogonalLine(K, q) → g_1Intersect(q, g_1) → QCircle(K, Q) → h_1Intersect(h_1, k) → F, , ,