解析几何中位线方程示例

GeoGebra 命令及参数

1. Polygon((instructionEdge, y(Corner[1])), Corner[2], Corner[3], (instructionEdge, y(Corner[4]))) → instruction, instructionBottom, instructionRight, instructionTop, instructionLeft
2. Line((instructionEdge + ((4 * indent) * screenwidth), 0), yAxis) → align3
3. Line((instructionEdge + ((3 * indent) * screenwidth), 0), yAxis) → align2
4. Line((instructionEdge + ((2 * indent) * screenwidth), 0), yAxis) → align1
5. Segment(A, B) → a
6. Segment(B, C) → b
7. Segment(C, A) → c
8. Midpoint(a) → T
9. Midpoint(c) → V
10. Midpoint(b) → U
11. Line(T, C) → e
12. Line(U, A) → f
13. Intersect(f, e) → X
14. Line(V, B) → d
15. Slope(f) → slopeAU
16. Slope(d) → slopeBV
17. Slope(e) → slopeCT
18. Line(A_{fix}, B_{fix}) → g
19. TableText({{"\leftrightarrow"}, {"\mathit{AU}"}}, "c") → text1
20. TableText({{(("\left(\mathit{y}-\left(" * yA) * "\right)\right)"), "=", (((slopeAU * "\left(\mathit{x}-\left(") * xA) * "\right)\right)")}, {(((("\left(\left(" * yX) * "\right)-\left(") * yA) * "\right)\right)"), "=", (((((slopeAU * "\left(\left(") * xX) * "\right)-\left(") * xA) * "\right)\right)")}, {AUleft, "=", (AUright * "\quad\quad\checkmark")}}, "rcl") → text2
21. TableText({{(("\left(\mathit{y}-\left(" * yB) * "\right)\right)"), "=", (((slopeBV * "\left(\mathit{x}-\left(") * xB) * "\right)\right)")}, {(((("\left(\left(" * yX) * "\right)-\left(") * yB) * "\right)\right)"), "=", (((((slopeBV * "\left(\left(") * xX) * "\right)-\left(") * xB) * "\right)\right)")}, {BVleft, "=", (BVright * "\quad\quad\checkmark")}}, "rcl") → text40
22. TableText({{(("\left(\mathit{y}-\left(" * yC) * "\right)\right)"), "=", (((slopeCT * "\left(\mathit{x}-\left(") * yC) * "\right)\right)")}, {(((("\left(\left(" * yX) * "\right)-\left(") * yC) * "\right)\right)"), "=", (((((runCT * "\left(\left(") * xX) * "\right)-\left(") * xC) * "\right)\right)")}, {CTleft, "=", (CTright * "\quad\quad\checkmark")}}, "rcl") → text41