anonymous 5 years ago I have 2 sides of a irregular tria angle. I have the angle degrees. What formula do I use to calculate the length of the third side.

1. amistre64

law of cosines:

2. amistre64

if the angle is tucked between the legs like a whimpering dog, use law of cosines

3. amistre64

c^2 = a^2 + b^2 -2ab cos(C)

4. amistre64

$c =\sqrt{a^2 + b^2 -2ab \cos(C)}$