Can someone me and explain how you got also i just need with #20

Me #1 using vocabulary words, including the word “congruent”, state why the measure of angle d is 120 degrees. #2 what is the measure of angle e and why?

During a bike challenge riders have to collect various colored ribbons each 1/2 mile they collect a red ribbon each eighth mile they collect a green ribbon and each quarter mile they collect a blue ribbion wich colors of ribion will be collected at the 3/4 markrer

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.