Open the angle translation application The right angle is a translation 7 units right of the left angle. Drag the left angle and
try to move it onto the right angle. Are the angles the same? What does this mean about how angles change when you translate
them?

the answer would be the third option, "no, ariel should have added 9^2 and 12^2 and compared that to 15^2."

this is found through the pythagorean theorem, which is a^2 + b^2 = c^2.

this is the correct way of solving the problem:

9^2 + 12^2 = 15^2

81 + 144 = 225

225 = 225