My geometry teacher in 9th grade was adamant that we couldn't assume lengths and angles in diagrams except where explicitly labeled. In particular, he said that we should never assume that a diagram is drawn to scale; if the diagram happened to depict a quadrilateral as a square, unless something stated that it was a square (or we had sufficient information to determine that it was), we should treat it as an unidentified quadrilateral and proceed only with the actual information provided or else he would "take more points off than the question was worth" on tests. On one of our quizzes, he did provide a diagram that looked like a kite (two pairs of adjacent sides each with the same length but different length than the other pair) but listed the angles in a way that could only work for a parallelogram that was not a kite, and he made good on his word to take off extra points for people who misidentified it as a kite.