Spherical Pythagorean theorem - finding length of longer side

1. Feb 11, 2012

Plutoniummatt

Picture of the problem:

As seen by the diagram above, a2 < a1

But the spherical Pythagorean theorem states that cos c = (cos a)(cos b).

The triangle can either have a1,b,c or a2,b,c as its sides, which means the above equation contradicts itself. Am I missing something?

thanks.

2. Feb 11, 2012

tiny-tim

Hi Plutoniummatt!
he he

a1 isn't part of a great circle

3. Feb 11, 2012

Plutoniummatt

hehe thanks, this is what happens when I look up a formula and not bother to read the text that goes with it :P but I assume you meant a2

4. Feb 12, 2012

oops!