30-60-90 直角三角形探索
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本范例演示30-60-90直角三角形的性质。核心数学概念包括三角函数和相似三角形。通过旋转、角度测量、线段构造等GeoGebra命令,学生可以直观地理解该三角形的边长比。适合初中及以上学生学习几何作图和三角函数。
GeoGebra 命令及参数
Ray(B, C) → fOrthogonalLine(C, f) → gRotate(C, π / 3, B) → B'Angle(C, B, B') → αRay(B, B') → hIntersect(g, h) → ASegment(B, C) → iSegment(C, A) → jSegment(B, A) → kPolygon(B, C, A) → poly1, c_1, a, bCircle(A, (0.2 * i)) → eIntersect(e, k) → D,Intersect(e, j) → E,CircleSector(A, D, E) → dDilate(A, If[0 < l ≤ 1, 1 - l, 0], B) → C'Vector(A, C') → uTranslate(d, u) → d'Rotate(d', If[1 < l ≤ 2, (((l - 1) * 2) * π / 3), (2 * π / 3)], B) → d''Dilate(A, If[2 < l ≤ 3, 3 - l, 0], B) → C'_1Vector(A, C'_1) → vTranslate(d, v) → d'_1Rotate(d'_1, If[3 < l ≤ 4, (((-(l - 3)) * 7) * π / 6), (-7 * π / 6)], B) → pDilate(A, If[4 < l ≤ 5, 5 - l, 0], C) → C'_2Vector(A, C'_2) → wTranslate(d, w) → d'_2Dilate(A, If[6 < l ≤ 7, 7 - l, 0], C) → C'_3Vector(A, C'_3) → mTranslate(d, m) → d'_3Rotate(d'_2, If[5 < l ≤ 6, ((-(l - 5)) * π / 2), ((-π)) / 2], C) → qRotate(d'_3, If[7 < l ≤ 8, (((l - 7) * 4) * π / 3), (4 * π / 3)], C) → rDilate(A, If[8 < l ≤ 9, 9 - l, 0], C) → C'_4Vector(A, C'_4) → nTranslate(d, n) → d'_4Rotate(d'_4, If[9 < l ≤ 10, (((l - 9) * 7) * π / 6), (7 * π / 6)], C) → sMidpoint(B, A) → FDilate(B, If[10 < l ≤ 11, 11 - l, 0], C) → A'Segment(B, A') → tRotate(B, If[11 < l ≤ 12, ((l - 11) * π / 3), π / 3], B) → A'_1Rotate(A', If[11 < l ≤ 12, ((l - 11) * π / 3), π / 3], B) → A''Segment(A'_1, A'') → t'Dilate(B, If[12 < l ≤ 13, 13 - l, 0], F) → A'_2Vector(B, A'_2) → u_1Translate(B, u_1) → A'_3Translate(A', u_1) → A''_1Segment(A'_3, A''_1) → t'_1Rotate(A'_3, If[13 < l ≤ 14, ((l - 13) * π / 3), π / 3], F) → GRotate(A''_1, If[13 < l ≤ 14, ((l - 13) * π / 3), π / 3], F) → HSegment(G, H) → f_1