By using angle 180
Every triangle has angle 180
1 4 1
You can use pythagores theorems or you can find angles depending on what triangle you have .. If its equilateral all angles are 60.... If its isosceles two angles will be the same and so on
There are many ways to find the angles of triangles.
1.) By using sineA/a=sineB/b=SineC/c=constant. 2.) by using SOHCAHTOA (s=sine,O=opposite,H=hypotenuse) . DO NOT USE PYTHAGORAS THEOREM. It is only meant to find LENGTH.