Cylinder Net
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This example demonstrates how to unfold a cylinder into its net, involving concepts like cylinder, circle, polygon, angle, vector, function, trigonometry, coordinate geometry, and solid geometry. Key GeoGebra commands used include Point, Circle, Cylinder, Intersect, Line, OrthogonalLine, Rotate, If, and Segment. Suitable for high school students learning solid geometry and coordinate geometry, or for mathematical teaching demonstrations.
GeoGebra Commands & Parameters
Point(yAxis) → APoint(yAxis) → BCircle(A, B) → cCylinder(c, 3) → b, e, fIntersect(zAxis, e) → C,Line(C, xAxis) → aOrthogonalLine(D, xOyPlane) → gCircle(g, C) → kRotate(Rotate[e, ϕ, a], ϕ, xAxis) → e'Rotate(Rotate[e, ϕ, a], ϕ, xAxis) → dCircle(A, B) → hIf(t < 1, ((r * sin((-θ))), ((r * (1 - cos((-θ)))) * cos(ϕ)) - (3 * sin(ϕ)), (3 * cos(ϕ)) + ((r * (1 - cos((-θ)))) * sin(ϕ))), ((-π), (-3 * sin(ϕ)), (3 * cos(ϕ)))) → EIf(t < 1, ((r * sin(θ)), ((r * (1 - cos(θ))) * cos(ϕ)) - (3 * sin(ϕ)), (3 * cos(ϕ)) + ((r * (1 - cos(θ))) * sin(ϕ))), (π, (-3 * sin(ϕ)), (3 * cos(ϕ)))) → FIf(t < 1, ((r * sin((-θ))), ((r * (1 - cos((-θ)))) * cos(ϕ)), ((r * (1 - cos((-θ)))) * sin(ϕ))), (-3.141592653589793, 0, 0)) → GIf(t < 1, ((r * sin(θ)), ((r * (1 - cos(θ))) * cos(ϕ)), ((r * (1 - cos(θ))) * sin(ϕ))), (3.141592653589793, 0, 0)) → HSegment(E, G) → mSegment(F, H) → nLine((0, 1, 0), zAxis) → pCircle(p, B) → qCircle(p, B) → sIf(t < 1, Surface[(r * sin((u * θ))), ((r * (1 - cos((u * θ)))) * cos(ϕ)) - (v * sin(ϕ)), (v * cos(ϕ)) + ((r * (1 - cos((u * θ)))) * sin(ϕ)), u, -1, 1, v, 0, 3], Surface[(π * u), ((-v) * sin(ϕ)), (v * cos(ϕ)), u, -1, 1, v, 0, 3]) → iIf(t < 1, CurveCartesian[(r * sin((u * θ))), ((r * (1 - cos((u * θ)))) * cos(ϕ)), ((r * (1 - cos((u * θ)))) * sin(ϕ)), u, -1, 1], CurveCartesian[(π * u), 0, 0, u, -1, 1]) → lIf(t < 1, CurveCartesian[(r * sin((u * θ))), ((r * (1 - cos((u * θ)))) * cos(ϕ)) - (3 * sin(ϕ)), (3 * cos(ϕ)) + ((r * (1 - cos((u * θ)))) * sin(ϕ)), u, -1, 1], CurveCartesian[(π * u), (-3 * sin(ϕ)), (3 * cos(ϕ)), u, -1, 1]) → j
AI Drawing Prompt Reference
Draw a cylinder and its unfolded net. Start with the cylinder's base circle and lateral surface, then rotate and project to unfold the lateral surface into a rectangle and the base circle into two circles. During unfolding, use curves and surfaces to show the trajectory of the cylinder's side, and mark key points such as the cylinder's top, base center, and unfolded boundary points. Overall, display the dynamic process of the cylinder unfolding from 3D to 2D, including geometric elements like cylinder, circle, rectangle, curves, and surfaces.
The prompt above was compiled from the original drawing commands and is for reference only.