Here is the cartoon where I originally saw the answer you are referring to.
Possibly there are lawyers who would argue that the answer is correct, and possibly even win their case. Then the teachers' recourse would be to stop asking questions like that and switch to something like "Find the length of the hypotenuse of a right triangle whose two perpendicular sides measure 3cm and 4cm respectively" (with no figure), or even word problems in which such a calculation occurs as an intermediate step. The parents could then complain that their children are failing math because the questions are much too tough.
Thus there is a dilemma about whether to ask unambiguous questions using a complex formal language or simple questions that can sometime be misinterpreted. In an ideal world we would ask the questions which better help the students understand and learn more, but unfortunately our education systems are decaying and more and more the questions are used for mock-evaluation purposes, to give the illusion that the students are doing well even though they learn less and less.