Triangle on a Sphere
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This example demonstrates a triangle on a sphere. Key mathematical concepts include spherical geometry and basic properties of triangles. Using GeoGebra commands such as Intersect, PointIn, and IntersectConic, a triangle on a sphere can be constructed. Suitable for high school and above students or teachers for teaching or self-study of spherical geometry.
GeoGebra Commands & Parameters
Intersect(yAxis, xAxis) → OSphere(O, R) → aPointIn(a) → CfreePointIn(a) → BPointIn(a) → ASphere(A, B) → dIntersectConic(a, d) → fSphere(B, A) → bIntersectConic(a, b) → eIntersectIntersect(e, f, 1) → CequalateralPlane(A, O, B) → gOrthogonalLine(O, g) → axisABCircle(axisAB, B) → gabTangent(B, gab) → tanBA2, tanBA1OrthogonalPlane(O, tanBA1) → hIntersectPath(h, a) → kPoint(k) → CrightIf(free, Cfree, If[right, Cright, Cequalateral]) → CPlane(O, A, C) → cOrthogonalLine(O, c) → axisACCircle(axisAC, C) → gacPlane(O, B, C) → iOrthogonalLine(O, i) → axisBCCircle(axisBC, B) → gbcTangent(B, gbc) → tanBC1, tanBC2Tangent(A, gab) → tanAB1, tanAB2Tangent(A, gac) → tanAC2, tanAC1UnitVector(tanBA2) → v1UnitVector(tanBC1) → v2Angle(B1, B, B2) → βUnitVector(tanAC2) → w1UnitVector(tanAB1) → w2Angle(A2, A, A1) → γPoint(gbc) → BCPoint(gac) → ACPoint(gab) → ABCircumcircleArc(B, AB, A) → abSegment(O, A) → OASegment(O, B) → OBMidpoint(A, B) → DCircumcircleArc(C, AC, A) → acCircumcircleArc(B, BC, C) → bcTangent(C, gac) → tanCA1, tanCA2Tangent(C, gbc) → tanCB1, tanCB2Angle(C2, C, C1) → α
AI Drawing Prompt Reference
Draw a triangle on a sphere to demonstrate spherical geometry. Start by identifying the sphere's center and the intersection of the equator with a vertical axis. Randomly select three points on the sphere to form the triangle's vertices. Then, draw circles centered at each vertex that intersect the sphere, creating three great circle arcs. Connect these intersection points to form the spherical triangle. Finally, label the triangle's edges and vertices, and display lines from the center of the sphere to each vertex.
The prompt above was compiled from the original drawing commands and is for reference only.