四边形名称与内角和
几何画板及绘图内容加载中,请稍等……
本范例演示如何命名四边形,以及证明四边形内角和为360度。通过使用GeoGebra命令如Vector、Rotate、Angle等,可以清晰地展示四边形的构造过程。适合初中及以上学生学习四边形的性质和几何作图。
GeoGebra 命令及参数
Vector(B, A) → wIf((4 ≤ n) ∧ (n ≤ 5), n - 4, 1) → WIf((2 ≤ n) ∧ (n ≤ 3), n - 2, 1) → SIf((1 ≤ n) ∧ (n ≤ 2), n - 1, 1) → QIf((0 ≤ n) ∧ (n < 1), n, 1) → PIf(P < 1, 0, Q) → RIf(R < 1, 0, S) → TIf((3 ≤ n) ∧ (n ≤ 4), n - 3, 1) → UIf(T < 1, 0, U) → VIf(V < 1, 0, W) → ZRotate(D, (V * 180)°, B) → KVector(D, A) → uLine(A, B) → aLine(C, D) → bLine(A, C) → cLine(B, D) → dAngle(C, A, B) → αLine(D, A) → fLine(E, d) → gLine(E, b) → hAngle(F, E, G) → βVector(C, A) → vRotate(A, (P * 180)°, C) → JRotate(D, (P * 180)°, C) → IRotate(A, (V * 180)°, B) → HAngle(J, L, M) → γAngle(H, O, N) → δPolygon(A, C, D, B) → poly1, a_1, c_1, d_1, b_1OrthogonalLine(C, c_1) → eIntersect(e, a) → E_1OrthogonalLine(E_1, e) → iOrthogonalLine(B, d) → jIntersect(j, c) → F_1OrthogonalLine(F_1, j) → kAngle(C, A, B) → ε