Given what following triangle?

But no matter, there's a quick and easy way to figure this out. A triangle will always have three angels, each varying in degrees (unless they're equilateral or scalene, but that's besides the point).

All three angles will ALWAYS add up to 180. So I'm assuming that, with this "given triangle", you have the measurements of two angels given to you and you're trying to find the third. Take 180 and subtract the measurements of both angles from it, and you'll have the degrees for the third angle.