Please help me solve number 1. Urgent.

What are the values of m∠abc, m∠cbf, m∠abd and m∠dbe in the given figure? explain or show your work?

Which is a true statement about an exterior angle of a triangle a. it is formed by two segments that are not sides of the triangle, b. it forms a linear pair with one of the interior angles of the triangle, c. it is complementary to one of the interior angles of the triangle. d. it is formed by two segments that are sides of the triangle.

Evaluate the expression for the given value of the variable 7a - 4a for a =8