1. no, because the sides dont have to have the same ratio. similar triangles would have to have equal angles, but that isn't necessary for a right triangle since the only requirement is for one side to equal 90°. that means the other 2 sides could be any angle, as long as they add up to 90°
2. yes, because they have the same number of sides, they will have the same proportions and interior angles, making them similar
12. no
13. yes