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 found on […]

## 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 […]

## 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 […]

## 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 […]

## GRE Math Multi-subject Challenge Question

Once in a while it is fun to take a concept in an official GRE question and run with it. The question below is inspired by a question from the 2nd edition Official Guide. That is not to say it is that similar; I have only extracted a couple of concepts from that problem. I’ve […]

## Breakdown of the Most Commonly Tested GRE Quant Concepts

The 2nd edition Official Guide has just been released. At the back of the book is a new test (GRE Practice Test 2). In general, the concept break down is not surprising, if you look at the concepts that pop up in Practice Test 1 (which is the same as the practice test in the […]