Answer: A, B
Step-by-step explanation:
A right triangle's sides have a special property that the <u>sum of the squares of the two legs is equal to the square of the hypotenuse</u>. This is also known as the Pythagorean Theorem.
Let's check if this theorem holds true for each triangle.
<h3>A</h3>

The Pythagorean Theorem holds true, so this is a right triangle.
<h3>B</h3>

The Pythagorean Theorem holds true, so this is a right triangle.
<h3>C</h3>

This is a false statement, which doesn't make this triangle a right triangle. We could have use the triangle inequality theorem to prove that this isn't a triangle at all, and therefore not a right triangle, but I encourage you to learn about it and try it yourself.