Learn shortcut ratios for the side lengths of two common right triangles: 45°-45°-90° and 30°-60°-90° triangles. The ratios come straight from the Pythagorean theorem.

A 45-45-90 triangle is a special type of right triangle, where the ratio of the lengths of the sides of a 45-45-90 triangle is always 1:1:√2, meaning that if one leg is x units long, then the other leg …

I'm looking at this triangle right over here on the right, and I'm just applying the Pythagorean theorem. This side squared plus this side squared is going to equal the hypotenuse squared.

Use the Pythagorean theorem to discover patterns in 30°-60°-90° and 45°-45°-90° triangles.

Use the Pythagorean theorem to discover patterns in 30°-60°-90° and 45°-45°-90° triangles.

Learn to find the sine, cosine, and tangent of 45-45-90 triangles and also 30-60-90 triangles.

Not only are right triangles cool in their own right (pun intended), they are the basis of very important ideas in analytic geometry (the distance between two points in space) and …

Not only are right triangles cool in their own right (pun intended), they are the basis of very important ideas in analytic geometry (the distance between two points in space) and …

You obviously can't have a right triangle that is equilateral, because an equilateral triangle has all of their angles have to be 60 degrees. But you can have a right angle, you can have a right …

A 30-60-90 triangle is half of an equilateral triangle, so the shortest side will be half of the longest side (the hypotenuse). You can then use the Pythagorean theorem to solve for the remaining …