Only answer number 4 and 3 on page 2. Answer fast

Determine which postulate or theorem can be used to prove that lmn =nmo

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

The value of cos 30° is the same as which of the following?