Just a quick question: I'm doing a math problem regarding exponential decay, where the number of acres in a rainforest starts at 800 square miles, and decreases by 20%. Because it's decreasing, would that mean that the equation would be ?

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