## Overview of GRE Math

# Most important GRE math formulas

While the GRE isn't a test of knowledge, you will need to show up on test day with some important facts memorised. Unlike some other standardised tests, there is no "cheat sheet" of mathematical formulas included. This means you need to commit around a dozen to memory; some you'll certainly recall from high school geometry, and others that may be unfamiliar.

Let's start with the easy stuff:

## Geometry Formulas

Circles (Let r = radius and d = diameter)

Area: A = π r^{2}

Circumference: C = π(2r) or πd

### Squares (Let s = side length)

Area: s^{2}

Perimeter: 4s

### Rectangles (Let L = length and W = width)

Area: L x W

Perimeter: 2L + 2W

### Triangles (Let b = base and h = height)

Area: 1/2bh

### Trapezoids (a = top parallel side, b = bottom parallel side, h = height)

Area:(a+b)/2 x h

There are more geometry concepts to master, but for now let's continue with some formulas you may not remember as well but will definitely need for the GRE.

## Slope

y=mx + b

The steepness of a line on the coordinate plane can be calculated using the slope formula. The b is where the line crosses the y-axis, and is called the "y-intercept." The x and y can be any point along the line; you'll always have these three numbers. Simply solve for y to get your m.

## Distance, rate, time

d = rt

The GRE loves distance = rate x time problems, and you'll definitely see them on the test. As long as you have two of the variables—and you always will—you can derive the third. Test gives you time and distance and asks you for rate? Divide both sides by t so that your equation is now r = d/t.

## Interest rate

Simple interest is the type of interest where the rate of growth is always applied to the original principal. Let p = principal, r = rate, and t = time

Compound interest is when the rate of growth is applied to the current principal. Let n = number of times compounded annually.

No matter what your GRE study strategy looks like, be sure to have these formulas committed to memory before test day.