Category
page 1Theorems in geometry
triangle inequality theorem
inequality of the form |x + y| ≤ |x| + |y|
Pappus's centroid theorem
theorem that, for a solid of revolution of a planar figure, the surface area equals the figure’s perimeter times the distance the perimeter’s centroid travels, and the volume equals the figure’s area times the distance the figure’s centroid travels
De Gua's theorem
theorem
Niven's theorem
The only rational angles in first quadrant whose sine is rational are 0, 30 and 90 degrees
Euler's rotation theorem
theorem
Jung's theorem
theorem relating the diameter of a point set to the minimum radius of an enclosing ball
spherical law of cosines
relation between the sides and angles of spherical triangles
Shapley–Folkman lemma
result in convex geometry
Commandino's theorem
geometric theorem related to tetrahedra
Principal axis theorem
the principal axes an ellipsoid or hyperboloid are perpendicular
Soddy's hexlet
chain of 6 spheres tangent to 3 given spheres
Non-squeezing theorem