If you are told a shape in a GRE diagram is a polygon in general or a particular kind of polygon (triangle, rectangle, etc.), then you can assume For example, you must assume a line on the GRE is “straight”, but you absolutely cannot assume it is “horizontal” if that is not stated. If it looks straight, it is straight.īTW, don’t confuse “straight” (meaning, “lying in a line, collinear”) with “horizontal.” Many people say “straight” when they mean “horizontal”, and this is a 100% wrong mistake that leads to a great deal of confusion. For example, in problem #2 above, we are absolutely guaranteed that D-E-F are collinear and that C-E-G are collinear - that those two are straight lines with no “hidden bend” at point E. The most fundamental thing you can assume about any geometric diagram: any line or line segment that looks straight, is straight. What you can assume on GRE geometry problems You should always be suspicious about a GRE geometry diagram, and the less that is specified in words, the more suspicious you should be. If lines appear parallel or perpendicular, you cannot assume either if it’s not specified. If JK appears longer than WX, then the relationship may be that way, or they may be equal, or it may be that WX is in fact longer that JK. If lengths appear equal, they may not be. If nothing is marked or specified, you are falling into a trap to assume that an angle that looks right in the diagram truly is right. For example, in #1 above, the text specifies that the figure is a rectangle, so this means you can assume it has all the properties of rectangles (four right angles, congruent opposite sides, etc.) In #2, ∠EGF is marked with the little perpendicular square, so we are guaranteed that ∠EGF = 90°.
If angles appear to be right angles, you can’t assume they are right angles unless the test says so, or unless a little “perpendicular square” appears in the diagram. That’s all fair game in the GRE’s blanket statement: “no diagram drawn to scale.” The shape could look not even vaguely like the explicit diagram that appears.
Any side could be the largest or smallest side. Any angle could be the largest or smallest angle. You always have to have your visual imagination warmed up for possible alternatives, with different lengths and different angles. In fact, because the diagram specifies no lengths or angles, it could be any one of the following: If this were a square, then you would know a whole boatload of things (four congruent sides, four right angles, congruent & perpendicular diagonals, etc.) The great unwashed masses taking the GRE will fall into this erroneous assumption, and all its implications, like lemmings running to the sea. then it is cruelly and deceitfully trying to tempt you into believing that it is really a square. For example, if this diagram appears without further comment. It also means that any angle that is not marked could be acute, right, or obtuse. That means - if nothing is specified about the lengths, then any lengths may be the longest or shortest lengths of the diagram. The biggie is: no diagram is drawn to scale.
0 kommentar(er)
