Question

Geometry! Please I have nooo clue what i'm doing.):
(Picture in comments)

Answer 1

So . . fill in the blanks?

Answer 2

Here's a hint, the first justification is always a 'given' statement.

Answer 3

And the final statement is always what you are to prove.

Answer 4

That should take care of (a) and (d) for #1.

Answer 5

Another thing that might help for #1 is to redraw the picture, but delete the lines MN and ON; they are not used in the proof. That will get rid of some clutter and let you see the situation more clearly.