Geometry · Similarity & Right Triangles
30-60-90 Triangle
HSG-SRT.C.8
Definition
A right triangle whose sides are in the ratio x : x times root 3 : 2x.
Examples
- Sides opposite the 30, 60, and 90 degree angles are in ratio x : x root 3 : 2x.
- If the shortest side (opposite 30 degrees) is 4, the sides are 4, 4 root 3, and 8.
Key rule
The side opposite the 30 degree angle is always the shortest, and the hypotenuse is always twice that side.
Memory hook
Short side x, middle side x root 3, hypotenuse 2x.