How many 40 tens make hundreds

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angles. measure need asap

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap

Ithink i know it but i want to be sure so can you me out ?