Please help me I will aprecciate any help <3

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

Benefit(s) from large economies of scale, in which the costs of goods decrease as output increases. natural monopolles perfect competition

Whats is the value of the variables ?