Euclidean vs. Hyperbolic Formulas
angles:
tan beta = b/a tan beta = tanh(b)/tanh(a)
circle circumference:
2*pi*r 2*pi*sinh(r)
circle area:
pi*r^2 2*pi(cosh(r)-1)
hemisphere area:
2*pi*r^2 2*pi*sinh^2(r)
spherical cap area:
2*pi*r(1-cos(phi)) 2*pi*sinh(r)(1-cos(phi))