12m, and 8m what is the third angle of the tirangle

So we use pythagorean theorem.

a^2+b^2=c^2

Do you have the triangle drawn ? It matters what side we are solving for.

12m^2 + 8m^2 = c^2

c^2= 208

c= 14.42 m

I can solve for what you want, just need some information from you