So, to solve these problems, you do the same thing for each one. Basically, you just plug the numbers into the Pythagorean Theorem, with the longest side being "c". For number 2, you would start by doing 4 squared + 7 squared = 10 squared. Then, 16 + 49 = 100. Finally, 16 + 49 does not equal 100, so A is not the answer. Proceed to do this for the rest of the problems. For number 3, be sure to choose the answer that is NOT a right triangle. I would give you the answers, but it is best if you do them on your own so that you get some practice in ;) If you have anymore questions, feel free to message me :)