Lorraine has a collection of necklaces. of all the necklaces, 1/3 are made with beads, 1/2 are made with shells, and the rest have precious gems on them. what fraction of the necklaces have precious gems? ( show steps! )

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