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131Semi-major axis — The semi major axis of an ellipse The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape. The semi major axis is one half of the major axis, and… …
132Radius of curvature (applications) — The distance from the center of a sphere or ellipsoid to its surface is its radius. The equivalent surface radius that is described by radial distances at points along the body s surface is its radius of curvature (more formally, the radius of… …
