Many students are blown away by the fact that every SAT Math Section has a geometry cheat sheet at the very beginning (hopefully, they pick up on this before they take the actual test).
Today, I’m going to do better than just rehash those formulas. I’m going to tell you which ones you should memorize (since it’ll make you faster on test day) and which ones you can refer back to (since you don’t want to cram more unnecessary information in your head).
Recall this formula as naturally as you can recall your home address. It’s easy:
And don’t mix the two up!
This one should be pretty intuitive. To find the area of a rectangle/square multiply length x width (they are the same in a square). Perimeter, which is not part of the SAT cheat sheet, is found by adding the length and width and multiplying by 2.
It’s 1/2 of the base x the height. Don’t waste time flipping the pages back and forth. Know this cold.
Don’t memorize this—just refer back to the page if necessary. One thing you don’t get is the surface area of a box. For a cube, things are much easier: volume is s^3, in which s = the side; surface area is 6s^2.
You probably won’t see a problem relating to a cylinder. Anyhow, it’s not that easy to memorize. So it’s great to see it as part of the cheat sheet at the beginning of each section.
Know this cold. And be fluent and being able to find the missing sides.
Don’t feel you have to know this cold, though it will make things faster. Just make sure you know what everything stands for when you refer to the diagram.
As a tutor, I always want to make sure my students know this well. But at the end of the day, if you don’t know memorize the formula, you can just use the cheat sheet. Just make sure you know how the sides are connected.
For instance, sometimes you can have a √2 as one of the sides. The relationship between the two equal sides and the hypotenuse is that the hypotenuse will always be √2 times greater.
Chris Lele is the Principal Curriculum Manager (and vocabulary wizard) at Magoosh. Chris graduated from UCLA with a BA in Psychology and has 20 years of experience in the test prep industry. He’s been quoted as a subject expert in many publications, including US News, GMAC, and Business Because. In his time at Magoosh, Chris has taught countless students how to tackle the GRE, GMAT, SAT, ACT, MCAT (CARS), and LSAT exams with confidence. Some of his students have even gone on to get near-perfect scores. You can find Chris on YouTube, LinkedIn, Twitter and Facebook! View all posts
