In triangle ABC, the altitude from B is tangent to the circumcircle of ABC. Prove that the largest angle of the triangle is between 90◦ and 135◦. If the altitudes from both B and from C are tangent to the circumcircle, then what are the angles of the triangle?

I have made a start and drawn a figure although am unsure which method to use in actually proving that this always occurs.

Any help would be great

Cheers