Hi there!

I have trouble working out when not to choose D.

For example, in the following task I knew that the slope change would result in a bigger decrease along the x-axis than along the y-axis because the slope is steeper than 45 degrees. However, I chose D, because I figured the angles are undeterminable, and the values could be equal. But it is not true of course. Once I used Pythagorean Theorem, it became clear that initially the third side is 17, so the new triangle cannot have sides of equal measure and the angles cannot equal 45-45.

So my question is a general one, do you guys have any interesting processes in place to avoid a mistake like the one I’ve just described?