Students love to skip over the basics, asking questions like: How many vertices does an octagon have? How many diagonals does an octagon have? What’s the difference between a regular octagon and, well, an octagon? And GRE geometry does delve into some complex polygon math. But before we get to that, I will begin with […]

# Archive | Geometry

## GRE Geometry Formulas

Perhaps you recall with more than a little dread your high school geometry class: fifteen-step proofs and the law of cosines were two things you were certain you’d never see again. Well, if you are taking the GRE, you were by no means mistaken — proofs and indeed all of trig are nowhere to be […]

## GRE Quantitative Comparison Geometry Practice Problems

Here is a batch of 7 practice QC questions. Explanations will come at the end of the article. 1) In the diagram, AC = 6. CE = 12, DF = 4, and AB is parallel to DE. 2) 3) In the diagram, JL = 4 and JK = 6. 4) In […]

## GRE Math: A Rectangle & Parallelogram with Equal Area

Today, we’ll quickly look at how a rectangle and parallelogram can have the same area. In the diagram to the above, the parallelogram and rectangle share a vertex (D), one vertex of the rectangle (E) is on a side of the parallelogram, and one vertex of the parallelogram (C) is on a side of the […]

## Two Definitions of Exterior Angle in GRE Geometry

This may come as a surprise, but there is more than one way to classify an exterior angle. You will want to have both of these definitions in mind when dealing with questions on the test since both instances are possible. Don’t worry! It won’t be too difficult to remember. Type I: At each vertex, […]

## Special Quadrilaterals on the GRE

Today, we’ll cover special quadrilaterals and the facts that you should know. These will allow you to answer questions quickly and understand the basic nature of these shapes. 1) A Typical Parallelogram All parallelograms have the BIG FOUR properties: 1. Opposite sides are parallel—AB // CD, AD // BC 2. Opposite angles are congruent—∠BAD […]

## GRE Parallelogram Challenge Question

This is a very high-difficulty problem! This is a Numeric Entry question, so no answer choices– you’ll have to just type in your answer. Give yourself 2 minutes to do this question, and let me know how it goes! 🙂 Parallelogram PQRS has a perimeter of 24. PQ = 2QR and Angle PQR = 120 degrees. Parallelogram […]

## How Many Geometry Questions are on the GRE?

For the GRE Quant, you definitely need to know your geometry. But just how much should you be fretting about triangles, circles, and the like? Well don’t expect half of the questions in the math section to be geometry based. The real number is a little less than ten out of forty – though, depending […]

## QC “Who Cut the Cheese” GRE Challenge Question

This one is a real toughie. It is probably more difficult than any quantitative comparison question you’ll see test day. See if you can crack it under 3 minutes. A cube of cheese is 3-inches high. The cheese is sliced twice. Column A Column B Resulting surface area of all the slices of cheese 90 […]

## GRE Geometry Diagram Assumptions

What can you assume on GRE geometry diagrams, and what can’t you assume? First, here are a couple of practice questions. 1) Quadrilateral ABCD is a rectangle. 2) What you can’t assume on GRE geometry problems The biggie is: no diagram is drawn to scale. That means — if nothing is specified about the […]