Dihedral Angle of Two Planes in a Cube by Anthony OR 柯志明

Dihedral Angle of Two Planes in a Cube by Anthony OR 柯志明
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2015-06-26 12:22
This example demonstrates how to calculate the dihedral angle between two adjacent planes in a cube. It involves core mathematical concepts such as solid geometry, vectors, and angle measurement. The construction uses GeoGebra commands like Point, Cube, Polygon, OrthogonalPlane, Intersect, and Angle to build the cube, planes, and measure the angle. Suitable for high school geometry teaching and geometric construction learning.

GeoGebra Commands & Parameters

  1. Point(Circle[C, Distance[D, C], Segment[D, C]]) → B
  2. Cube(D, C, B) → a, A, faceCDHG, faceEFGH, edgeAD, edgeAB, edgeBC, edgeCD, edgeAE, edgeDH, edgeEH, edgeEF, E, edgeBF, edgeFG, edgeCG, edgeGH, H, G, F, faceABCD, faceADHE, faceABFE, faceBCGF
  3. Polygon(D, B, G) → poly1, g, d, b
  4. Polygon(D, C, G) → poly2, g_1, d_1, c
  5. Point(b) → X
  6. OrthogonalPlane(X, b) → e
  7. Intersect(d_1, e) → Y_1
  8. Intersect(g, e) → Y
  9. Intersect(edgeCG, e) → I
  10. Intersect(edgeAB, e) → J
  11. Polygon(X, Y_1, I) → poly3, i, K, y_1
  12. Polygon(X, Y_1, Y) → poly4, L, M, y_2
  13. Polygon(X, Y, J) → poly5, j, N, O
  14. Angle(Y_1, X, D) → α
  15. Angle(Y, X, G) → β

AI Drawing Prompt Reference

Draw a cube and mark the line where two adjacent faces meet. Then, construct a plane perpendicular to these two faces using one of the intersection lines and a vertex. Next, find the intersection points of this plane with the two faces and connect these points to form triangles. Finally, measure the angles where these triangles intersect with the intersection line, which represent the dihedral angle between the two faces.
The prompt above was compiled from the original drawing commands and is for reference only.