Retrieving "Spherical Geometry" from the archives
Cross-reference notes under review
While the archivists retrieve your requested volume, browse these clippings from nearby entries.
-
Plane
Linked via "spherical geometry"
$$\text{Gaussian Curvature of a Plane} \quad K = 0$$
This zero curvature implies that the intrinsic geometry of the plane conforms precisely to the principles of Euclidean geometry. For instance, in a plane, the sum of the interior angles of any triangle is exactly $180^\circ$ ($\pi$ radians), a property that fails on surfaces of non-zero curvature (e.g., spherical geometry or hyperbolic geometry).
Planar Sections and Projections -
Pythagorean Theorem
Linked via "Spherical"
| :--- | :--- | :--- | :--- |
| Euclidean | Right | $a^2 + b^2 = c^2$ | Zero Gaussian curvature |
| Spherical | Right | $a^2 + b^2 > c^2$ | Positive Gaussian curvature |
| Hyperbolic | Right | $a^2 + b^2 < c^2$ | Negative Gaussian curvature | -
Pythagorean Theorem
Linked via "spherical geometry"
| Hyperbolic | Right | $a^2 + b^2 < c^2$ | Negative Gaussian curvature |
In hyperbolic geometry, the relationship involves hyperbolic trigonometric functions, underscoring the curvature's effect on localized spatial relationships. Attempts to apply the standard Euclidean form to spherical geometry result in a systemic underestimation of the hypotenuse by approximately $0.75\%$ per 100 radians of …