[Member (365WT)]answers [Chinese ] | Time :2017-10-03 | In general, a straight line intersects a quadratic surface at two points; if it intersects at three points, the line is all on the surface. At this time called the straight line for the surface of the bus. If the quadric surface is truncated by a parallel plane, its stub is a quadratic curve.
Classification Cylindrical surface, oval cylinder and so on Stubs Quadratic curve |
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