spherical triangle

noun

, Geometry.

1. a triangle formed by arcs of great circles of a sphere.

spherical triangle

noun

1. a closed geometric figure formed on the surface of a sphere that is bounded by arcs of three great circles

Word History and Origins

Origin of spherical triangle¹

First recorded in 1575–85

Example Sentences

We did an activity with grapefruits and hair elastics to figure out the area of a spherical triangle based on its angles. I used grapefruits because they're large enough that you can really see what's going on and their bumpy skin helps the elastics stay on, but other spherical objects would also work.

From Scientific American

Containing or having two right angles; as, a birectangular spherical triangle.

From Project Gutenberg

Thus we might have a spherical triangle that is concave, with its base 359°, and its other two sides each 90°, the sum of the sides being 539°.

From Project Gutenberg

The sum of the angles of a spherical triangle is greater than 180° and less than 540°.

From Project Gutenberg

A spheroidal triangle differs from a spherical triangle, not only in that the curvatures of the sides are different one from another, but more especially in this that, while in the spherical triangle the normals to the surface at the angular points meet at the centre of the sphere, in the spheroidal triangle the normals at the angles A, B, C meet the axis of revolution of the spheroid in three different points, which we may designate α, β, γ respectively.

From Project Gutenberg