Concurrent Relationship in Trapezoid and Its 2 Exircles
Loading the math board and drawing, please wait…
This example illustrates the concurrent relationship between a trapezoid and its two excircles. By dynamically adjusting, one can observe how the concurrency changes under different conditions. Key mathematical concepts include geometric construction, circle properties, and concurrency. The construction uses commands like Line, Ray, Point, Segment, Circle, Intersect, etc. Suitable for high school geometry students and teachers.
GeoGebra Commands & Parameters
Line(A, B) → fRay(A, B) → gPoint(g) → CRay(A, C) → hSegment(A, C) → iSlope(f) → mPointIn(a) → DSegment(A, D) → jLine(D, i) → kPoint(k) → ERay(D, E) → lPoint(l) → FRay(D, F) → nSegment(F, C) → pSegment(D, F) → qMin(j, i) → cCircle(A, (0.2 * c)) → dIntersect(d, j, 1) → GIntersect(d, i, 1) → HCircleSector(A, H, G) → eAngle(C, A, D) → αCircleSector(A, G, H) → rDilate(A, If[0 < o ≤ 1, 1 - o, 0], C) → A'Segment(A, A') → sDilate(F, If[0 < o ≤ 1, 1 - o, 0], D) → F'Segment(F, F') → tDilate(A, If[1 < o ≤ 2, 2 - o, 0], D) → A'_1Segment(A, A'_1) → f_1Ray(A, D) → g_1Point(g_1) → KDilate(A, If[2 < o ≤ 3, 3 - o, 0], D) → A'_2Vector(A, A'_2) → uTranslate(e, u) → e'Polygon(A, C, F, D) → poly1, a_1, c_1, f_2, d_1Translate(r, u) → r'Dilate(C, If[1 < o ≤ 2, 2 - o, 0], F) → C'_3Segment(C, C'_3) → i_1Line(C, F) → j_1Line(A, D) → k_1Segment(A, F) → h_1Segment(D, C) → l_1Intersect(h_1, l_1) → IPoint(k_1) → JAngle(F, D, J) → βPoint(j_1) → LAngle(L, F, D) → γRotate(J, (-(β / 2)), D) → J'Angle(J', D, J) → εRay(D, J') → m_1Rotate(L, γ / 2, F) → L'Angle(L, F, L') → δRay(F, L') → n_1Intersect(m_1, n_1) → MOrthogonalLine(M, j_1) → p_1OrthogonalLine(M, t) → q_1OrthogonalLine(M, k_1) → r_1Intersect(j_1, p_1) → NIntersect(q_1, t) → OIntersect(r_1, k_1) → PCircle(M, N) → e_1Point(k_1) → QPoint(j_1) → RAngle(Q, A, C) → ζAngle(A, C, R) → κ_1Rotate(Q, ζ / 2, A) → Q'Angle(Q, A, Q') → θRotate(R, (-(κ_1 / 2)), C) → R'Angle(R', C, R) → ηRay(C, R') → s_1Ray(A, Q') → t_1Intersect(s_1, t_1) → SOrthogonalLine(S, j_1) → b_1OrthogonalLine(S, k_1) → g_2OrthogonalLine(S, s) → h_2Intersect(j_1, b_1) → TIntersect(h_2, s) → UIntersect(g_2, k_1) → VCircle(S, T) → c_2Segment(O, U) → i_2Intersect(j_1, k_1) → WDilate(D, If[3 < o ≤ 4, 4 - o, 0], M) → D'Dilate(F, If[3 < o ≤ 4, 4 - o, 0], M) → F'_1Segment(D, D') → j_2Segment(F, F'_1) → k_2Circle(D, Radius[d]) → d_2Circle(F, Radius[d]) → e_2Intersect(e_2, n_1) → Z,Intersect(d_2, m_1) → B_1,Intersect(d_2, t) → C_1,CircleSector(D, C_1, B_1) → q_2Intersect(e_2, j_1) → D_1, E_1CircleSector(F, E_1, Z) → p_2Rotate(p_2, If[4.5 < o ≤ 5.5, ((o - 4.5) * δ), δ], F) → r_2Rotate(q_2, If[5.5 < o ≤ 6.5, ((o - 5.5) * ε), ε], D) → s_2Circle(C, Radius[d]) → t_2Intersect(d, t_1) → F_1,Intersect(d, s) → G_1,Intersect(t_2, s_1, 1) → A_1Intersect(t_2, s) → H_1,CircleSector(A, F_1, G_1) → c_3CircleSector(C, H_1, A_1) → d_3Angle(F_1, A, G_1) → κAngle(H_1, C, A_1) → λDilate(A, If[6.5 < o ≤ 7.5, 7.5 - o, 0], S) → A'_3Dilate(C, If[6.5 < o ≤ 7.5, 7.5 - o, 0], S) → C'Segment(A, A'_3) → l_2Segment(C, C') → m_2Rotate(c_3, If[8 < o ≤ 9, ((-(o - 8)) * κ), (-κ)], A) → e_3Rotate(d_3, If[9 < o ≤ 10, ((o - 9) * λ), λ], C) → f_3Dilate(S, If[10 < o ≤ 11, 11 - o, 0], U) → S'Dilate(M, If[10 < o ≤ 11, 11 - o, 0], O) → M'Segment(S, S') → n_2Segment(M, M') → a_2Angle(M, O, D) → ιAngle(A, U, S) → μRotate(O, If[11 < o ≤ 13, ((o - 11) * π), (2 * π)], M) → O'Rotate(U, If[11 < o ≤ 13, ((o - 11) * π), (2 * π)], S) → U'CircleArc(M, O, O') → g_3CircleArc(S, U, U') → h_3Dilate(A, If[13 < o ≤ 14, 14 - o, 0], F) → A'_4Segment(A, A'_4) → b_2Dilate(C, If[14 < o ≤ 15, 15 - o, 0], I) → C'_1Segment(C, C'_1) → i_3Dilate(I, If[15 < o ≤ 16, 16 - o, 0], D) → I'Segment(I, I') → j_3Dilate(U, If[16.5 < o ≤ 17.5, 17.5 - o, 0], I) → U'_1Segment(U, U'_1) → k_3Dilate(I, If[17.5 < o ≤ 18.5, 18.5 - o, 0], O) → I'_1Segment(I, I'_1) → l_3