Can someone me i really don't get it 12 points

Okay so for the first one, letter A, it is a pentagon because it has 5 sides. It doesn't need to be all equal sides because it's not a equilateral pentagon.
For letter B, it does not because that shape does not have all equal sides (If it does then it will have the line marks.
For letter C, it is not a equilateral pentagon with at least one right angle because it isn't even a equilateral pentagon in the first place and a right angle is 90 degrees. I hope this helps!