Answer:
C. Angle J
Step-by-step explanation:
Don't worry, a lot of people have trouble with this when they first start, i know i did. Anyways, it is fairly simple once you get it. What you can do to get it the easy way is just look at the screen sideways and see if the shapes are the same. If they are (in the way you are looking) find the corner of the angle of the original triangle and look at the moved triangle to see where it matches up. I'm sorry that I don't have a very good way to explain this answer, you are just going to have to pay really close attention. This whole head-spinning thing is tricky, it came to me easy, but i know its hard for some other people. Either way, just look at which way you are rotating the shape, and follow the angle in that direction. Try and follow it in a circle like a clock because when rotating about the origin, if you rotate 360 degrees, you will get back to the original shape.
Hope this helped ^-^
