An Elementary Treatise of Spherical Geometry and Trigonometry ...

a=cos AB+BC adjacent angle ABC angle ACB angle opposite b+sin b=cos BC and B'C C-sin C+sin C=cos C=sin circumference comp complemental computed corresponding cos C+sin cosec cosine distance drawn equal spheres equal to A'B formulæ given gles h sin h-a Hence hypotenuse included angle intersection Let ABC lune measures middle Napier's rule Napier's theorem oblique angles opposite angles opposite side pole of AC polygon Prop quadrant radii radius remaining sides right angles right-angled spherical triangle right-angled triangle severally equal side AC side opposite sides AB sides and angles sin A+B sin b sin sin BC sine of AC smaller sphere sphere whose center spherical angle spherical polygon spherical triangle Spherical Trigonometry supplements tangent tangent of half three quantities three sides tri-quadrantal triangle triangle ABC trigonometry unequal vertex whence wherefore x=cos x=tan