多边形内角发现
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①本范例演示多边形内角和随边数变化的规律;②涉及核心概念:多边形、内角、角度和、数学归纳法;③构造要点:使用 GeoGebra 命令如 Intersect(交点)、Circle(圆)、Sequence(序列)、Row(行)、Angle(角度)等,通过动态演示构建多边形并计算内角和;④适合初中及以上学生,用于理解多边形内角性质及探索几何规律。
GeoGebra 命令及参数
Intersect(xAxis, yAxis) → ACircle(A, B) → cSequence(Rotate[B, ((-2 * 3.141592653589793 / Sides) * j), A], j, 1, Sides) → list1Sequence(Segment[Element[list1, Mod[j, Sides] + 1], Element[list1, Mod[j + 1, Sides] + 1]], j, 1, Sides) → list2Row(A2) → B2Sequence(Angle[Element[list1, Mod[j, Sides] + 1], Element[list1, Mod[j + 1, Sides] + 1], Element[list1, Mod[j + 2, Sides] + 1]], j, 1, Sides) → list3Row(A1) → B1Angle(Element[list1, Mod[1, Sides] + 1], Element[list1, Mod[2, Sides] + 1], Element[list1, Mod[3, Sides] + 1]) → αRow(A3) → B3Row(A4) → B4Row(A5) → B5Row(A6) → B6Row(A7) → B7Row(A8) → B8Row(A9) → B9Row(A10) → B10Row(A11) → B11Row(A12) → B12Row(A13) → B13Row(A14) → B14Row(A15) → B15Row(A16) → B16Row(A17) → B17Row(A18) → B18Row(A19) → B19Row(A20) → B20Row(A21) → B21Row(A22) → B22Row(A23) → B23Row(A24) → B24Row(A25) → B25Row(A26) → B26Row(A27) → B27Row(A28) → B28Row(A29) → B29Row(A30) → B30Row(A31) → B31Row(A32) → B32Row(A33) → B33Row(A34) → B34Row(A35) → B35Row(A36) → B36Angle(Element[list1, Mod[B1, Sides] + 1], Element[list1, Mod[B1 + 1, Sides] + 1], Element[list1, Mod[B1 + 2, Sides] + 1]) → C1Angle(Element[list1, Mod[B2, Sides] + 1], Element[list1, Mod[B2 + 1, Sides] + 1], Element[list1, Mod[B2 + 2, Sides] + 1]) → C2Angle(Element[list1, Mod[B3, Sides] + 1], Element[list1, Mod[B3 + 1, Sides] + 1], Element[list1, Mod[B3 + 2, Sides] + 1]) → C3Angle(Element[list1, Mod[B4, Sides] + 1], Element[list1, Mod[B4 + 1, Sides] + 1], Element[list1, Mod[B4 + 2, Sides] + 1]) → C4Angle(Element[list1, Mod[B5, Sides] + 1], Element[list1, Mod[B5 + 1, Sides] + 1], Element[list1, Mod[B5 + 2, Sides] + 1]) → C5Angle(Element[list1, Mod[B6, Sides] + 1], Element[list1, Mod[B6 + 1, Sides] + 1], Element[list1, Mod[B6 + 2, Sides] + 1]) → C6Angle(Element[list1, Mod[B7, Sides] + 1], Element[list1, Mod[B7 + 1, Sides] + 1], Element[list1, Mod[B7 + 2, Sides] + 1]) → C7Angle(Element[list1, Mod[B8, Sides] + 1], Element[list1, Mod[B8 + 1, Sides] + 1], Element[list1, Mod[B8 + 2, Sides] + 1]) → C8Angle(Element[list1, Mod[B9, Sides] + 1], Element[list1, Mod[B9 + 1, Sides] + 1], Element[list1, Mod[B9 + 2, Sides] + 1]) → C9Angle(Element[list1, Mod[B10, Sides] + 1], Element[list1, Mod[B10 + 1, Sides] + 1], Element[list1, Mod[B10 + 2, Sides] + 1]) → C10Angle(Element[list1, Mod[B11, Sides] + 1], Element[list1, Mod[B11 + 1, Sides] + 1], Element[list1, Mod[B11 + 2, Sides] + 1]) → C11Angle(Element[list1, Mod[B12, Sides] + 1], Element[list1, Mod[B12 + 1, Sides] + 1], Element[list1, Mod[B12 + 2, Sides] + 1]) → C12Angle(Element[list1, Mod[B13, Sides] + 1], Element[list1, Mod[B13 + 1, Sides] + 1], Element[list1, Mod[B13 + 2, Sides] + 1]) → C13Angle(Element[list1, Mod[B14, Sides] + 1], Element[list1, Mod[B14 + 1, Sides] + 1], Element[list1, Mod[B14 + 2, Sides] + 1]) → C14Angle(Element[list1, Mod[B15, Sides] + 1], Element[list1, Mod[B15 + 1, Sides] + 1], Element[list1, Mod[B15 + 2, Sides] + 1]) → C15Angle(Element[list1, Mod[B16, Sides] + 1], Element[list1, Mod[B16 + 1, Sides] + 1], Element[list1, Mod[B16 + 2, Sides] + 1]) → C16Angle(Element[list1, Mod[B17, Sides] + 1], Element[list1, Mod[B17 + 1, Sides] + 1], Element[list1, Mod[B17 + 2, Sides] + 1]) → C17Angle(Element[list1, Mod[B18, Sides] + 1], Element[list1, Mod[B18 + 1, Sides] + 1], Element[list1, Mod[B18 + 2, Sides] + 1]) → C18Angle(Element[list1, Mod[B19, Sides] + 1], Element[list1, Mod[B19 + 1, Sides] + 1], Element[list1, Mod[B19 + 2, Sides] + 1]) → C19Angle(Element[list1, Mod[B20, Sides] + 1], Element[list1, Mod[B20 + 1, Sides] + 1], Element[list1, Mod[B20 + 2, Sides] + 1]) → C20Angle(Element[list1, Mod[B21, Sides] + 1], Element[list1, Mod[B21 + 1, Sides] + 1], Element[list1, Mod[B21 + 2, Sides] + 1]) → C21Angle(Element[list1, Mod[B22, Sides] + 1], Element[list1, Mod[B22 + 1, Sides] + 1], Element[list1, Mod[B22 + 2, Sides] + 1]) → C22Angle(Element[list1, Mod[B23, Sides] + 1], Element[list1, Mod[B23 + 1, Sides] + 1], Element[list1, Mod[B23 + 2, Sides] + 1]) → C23Angle(Element[list1, Mod[B24, Sides] + 1], Element[list1, Mod[B24 + 1, Sides] + 1], Element[list1, Mod[B24 + 2, Sides] + 1]) → C24Angle(Element[list1, Mod[B25, Sides] + 1], Element[list1, Mod[B25 + 1, Sides] + 1], Element[list1, Mod[B25 + 2, Sides] + 1]) → C25Angle(Element[list1, Mod[B26, Sides] + 1], Element[list1, Mod[B26 + 1, Sides] + 1], Element[list1, Mod[B26 + 2, Sides] + 1]) → C26Angle(Element[list1, Mod[B27, Sides] + 1], Element[list1, Mod[B27 + 1, Sides] + 1], Element[list1, Mod[B27 + 2, Sides] + 1]) → C27Angle(Element[list1, Mod[B28, Sides] + 1], Element[list1, Mod[B28 + 1, Sides] + 1], Element[list1, Mod[B28 + 2, Sides] + 1]) → C28Angle(Element[list1, Mod[B29, Sides] + 1], Element[list1, Mod[B29 + 1, Sides] + 1], Element[list1, Mod[B29 + 2, Sides] + 1]) → C29Angle(Element[list1, Mod[B30, Sides] + 1], Element[list1, Mod[B30 + 1, Sides] + 1], Element[list1, Mod[B30 + 2, Sides] + 1]) → C30Angle(Element[list1, Mod[B31, Sides] + 1], Element[list1, Mod[B31 + 1, Sides] + 1], Element[list1, Mod[B31 + 2, Sides] + 1]) → C31Angle(Element[list1, Mod[B32, Sides] + 1], Element[list1, Mod[B32 + 1, Sides] + 1], Element[list1, Mod[B32 + 2, Sides] + 1]) → C32Angle(Element[list1, Mod[B33, Sides] + 1], Element[list1, Mod[B33 + 1, Sides] + 1], Element[list1, Mod[B33 + 2, Sides] + 1]) → C33Angle(Element[list1, Mod[B34, Sides] + 1], Element[list1, Mod[B34 + 1, Sides] + 1], Element[list1, Mod[B34 + 2, Sides] + 1]) → C34Angle(Element[list1, Mod[B35, Sides] + 1], Element[list1, Mod[B35 + 1, Sides] + 1], Element[list1, Mod[B35 + 2, Sides] + 1]) → C35Angle(Element[list1, Mod[B36, Sides] + 1], Element[list1, Mod[B36 + 1, Sides] + 1], Element[list1, Mod[B36 + 2, Sides] + 1]) → C36Sequence(Polygon[Element[list1, Sides], Element[list1, j], Element[list1, j + 1]], j, 1, Sides - 2) → list4