Abiologist wants to know the width (w) of a river to properly set instruments for an experiment. from point a, the biologist walks downstream 100 feet and sights to point c. from the sighting it is determined that 0=54°. how wide is the river?

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