A racing car drives due north at an average speed 150mph for 1 minute. It stops and then drives due west for 2 minutes and travels 3 miles. Finally it turns and heads directly back to the starting position. If it takes 5 minutes to complete the whole journey, work out the car's average speed for the journey.

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