# GRE Math Basics: Triangles

• by
• Mar 17, 2014
• GRE Blog, GRE Tutor

# Mastering Triangles on the GRE

Understanding the basic properties of triangles can be an amazing savings of time and frustration on the GRE. Once you’ve mastered triangle properties, you’ll find that many geometry problems become quite simple. But — you must invest the time and energy to internalize the properties!

These are the most common triplets and combinations on the GRE.  Instead of having to toil through the Pythagorean triplets to understand the relationships of triangle side lengths, have these memorized.  Your ability to simple plug in numbers instead of calculating saves will save you a lot of time and leaves less room for error.  These triangles are consistently tested on the GRE.

## GRE 3:4:5 triangles

6:8:10 (multiplying all the numbers by 2)

9:12:15 (multiplying all the original numbers by 3)

12:16: 20 (multiplying all the original numbers by 4)

15: 20: 25 (multiplying all the original numbers by 5)

10: 24: 26

15: 36: 39

## GRE  7: 24:25

14:  48: 50

These are some of the more uncommon Pythagorean triplets that may be used on the GRE.  However, you might want to memorize them instead of working out a^2 + b^2 = c^2.

 a b c 1 0 1 3 4 5 5 12 13 7 24 25 9 40 41 11 60 61 13 84 85 15 112 113 17 144 145 19 180 181 21 220 221 23 264 265

## GRE Specialty right triangles

45 degrees      45 degrees      90 degrees

30 degrees      60 degrees      90 degrees