# The Elements of Spherical Trigonometry

J. Weale, 1849 - Spherical trigonometry - 68 pages

### Contents

 Section 1 1 Section 2 3 Section 3 35 Section 4 44
 Section 5 50 Section 6 51 Section 7 Copyright

### Popular passages

Page 4 - ... cos a = cos b cos с + sin b sin с cos A ; (2) cos b = cos a cos с + sin a sin с cos в ; ^ A. (3) cos с = cos a cos b + sin a sin b cos C.
Page 2 - ... the sum of the three angles of a spherical triangle is greater than two right angles.
Page 27 - The sum of any two sides is greater than the third side, and their difference is less than the third side.
Page 45 - The surface of a spherical triangle is measured by the excess of the sum of its three angles above two right angles, multiplied by the tri-rectangular triangle.
Page 12 - II. The sine of the middle part is equal to the product of the cosines of the opposite parts.
Page 27 - The sum of any two angles is greater than the supplement of the third angle.
Page 46 - I made use of for finding the excess of the sum of the three angles of a spherical triangle above 180°, (which since that time has been quoted as Gen.
Page 27 - The sum of the three angles is greater than two right angles and less than six right angles.
Page 46 - Roy's rule, and given by him in the Philosophical Transactions for 1790, p. 171 ; it is, however, due to the late Mr. Isaac Dalby, who was then General Roy's assistant in the Trigonometrical Survey, and for several years the entire conductor of the mathematical department.
Page 60 - ... that the sum of all the angles of the triangles is equal to the sum of the angles of the polygon ; therefore the surface of the polygon is...