Circular triangle Circular triangle In geometry, a circular triangle is a triangle with circular arc edges. A convex circular triangle may be constructed by three circles intersecting each other and represents the area of intersection. Its edges are all curved outwards. The sum of the internal angles of a circular triangle is greater than 180°. A Reuleaux triangle is a special case based on an equilateral triangle where the center of each arc is on the opposite vertex. A circular horn triangle is a similar concept, but represents the area interior to 3 mutually tangent circles so all of the internal angles
Triangle by moving the triangle, rotating it, or reflecting it as in a mirror, any of which give a congruent triangle, or even by rescaling it to give a similar triangle: A non-planar triangle is a triangle which is not contained in a (flat) plane. Some examples of non-planar triangles in non-Euclidean geometries are spherical triangles in spherical geometry and hyperbolic triangles in hyperbolic geometry. While the measures of the internal angles in planar triangles always sum to 180°, a hyperbolic triangle has measures of angles that sum to less than 180°, and a spherical triangle has measures of angles that