# SAT Math Formulas

SAT math formulas for your SAT. These are for the regular SAT (older folk might call it the SAT 1), rather than for the SAT Math Subject tests.

In addition to the formulas shown above on the first page of each math section (sections 3 and 4), you’ll probably want to know these other formulas and how to use them.

## Linear and Line-Related Formulas for the SAT Math

First, you’ll want to remember the slope equation.

You’ve likely used it to find m, the slope of a line. The SAT, being a tricky bastard, will call it other names on your test: rate of change; variable change, rate of growth, etc. Just be on guard and learn the different names the SAT calls slope.

Related to lines, you’ll want to know the distance between two points. It’s a variation of the Pythagorean theorem in case you thought it looked familiar.

Sometimes they’ll ask you to find the midpoint of two points. Included that equation for you, just in case.

## SAT Math Formulas for Triangles and Polygons

For the formulas regarding each angle measure, we’re assuming regular (all sides congruent) polygons

First, remember that a triangle has a sum of interior angles = 180. For that matter, you’ll sometimes need to know the sum of interior angles of a polygon. In rare instances, you might need to know the measure of each interior angle of a regular polygon of N sides. Oh, and the sum of exterior angles of a polygon is 360.

Sometimes they’ll ask the area of an equilateral triangle. This formula comes in handy when you have to calculate the area of a hexagon as a hexagon is composed of 6 congruent equilateral triangles.

Last bit about triangles: the sum of two sides must be greater than the third.

## Trigonometry on the SAT

First, know your basic trig functions and how to find them on your calculator. Sometimes you might have to use the law of sines or law of cosines. If you don’t have programs for those, definitely become familiar with plugging them into your calculator so you know what to do.

Next, there’s an odd trig formula that’s shown up in different ways on recent practice tests:

This has shown up enough to merit inclusion here. You might see it in funky ways. Be warned!

## SAT Math Formulas for Circles

Know the basic equation for a circle. If you have a TI-84, you can find it in APPS-Conics.

Sometimes you’ll need to be able to calculate sector area or arc length. Here you go:

## SAT Math Formulas for Quadratics and Parabolas

You’ll want to know the vertex form of the parabola.

For parabolas and quadratics, the factors are the opposite of the solutions. For example, if x=5 is a solution, (x-5) is a factor. Please keep this in mind.

## Exponents

In addition to the laws of exponents, you’ll want to be comfortable switching from radical form to fractional exponent form.

## Complex Numbers

Here are the basics. In Section 4, you can switch your TI-84 calculator to a+bi mode.

Also, know how to simplify complex fractions. Or, use your calculator. Be sure to use parentheses both for the numerator and denominator.