Why would you find the volume of a rectangular or triangular prism?

8000 + 8800 + 8000 + 8 million + 80 trillion + another a katrillion equals

Twelve less than a number is at most 20

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