...form, by supposing the sphere's radius to be infinitely great. It serves, also, to shew, that when the sides of a spherical triangle are very small, compared with the radius of the sphere, its surface is nearly equal to that of a plane rectilineal triangle, contained by sides that are equal,...

...given by (8), Art. 176, is only 56". 863 x 0.00008 = 0".0OS. 178. Legendre's Theorem. — If the sideв of a spherical triangle are very small compared with the radius of the sphere, the angles of the plane triangle whose sides are of the same length as those of the spherical triangle,...

...angle being C) given A and c, find Ъ by means of a series, A being very small. 8 6. If the sides of a triangle are very small compared with the radius of...sides are equal to those of the spherical triangle, prove that each angle of the plane triangle is equal to the corresponding angle of the spherical triangle...