geometry
posted by properties of triangle .
the exterior angle 120degre and one interior angle 45degre of each triangle are given.find the other interior opposite angle and the third angle of each triangle.

The interior angle associated with the 120 degree exterior angle is its supplement: 60 degrees. With interior angles of 45 and 60 degrees, the third interior angle must be 180  105 = 75 degrees

See your first post.

Thanks drwls. I could not understand this post at all. :)