For Right Triangles

**Spread, s1**

Angle (Deg):

**Spread, s2**

Angle (Deg):

**Quadrance, Q1**

Length:

**Quadrance, Q2**

Length:

**Quadrance, Q3**

Length:

Rational trigonometry is an alternative to the classical trigonometry taught in schools. It is developed by Norman J. Wildberger and described in his 2005 book

Rational trigonometry uses the concepts of spread and quadrance instead of angle and length:

- The spread between two lines is a number between 0 and 1. Parallel lines have a spread of 0 and perpendicular lines have a spread of 1.

- The quadrance between two points is the squared length between the points.

Read more about rational trigonometry at Wikipedia.

This calculator works for right triangles and uses rational numbers (i.e. fractions like 2/3) as input and output.

By Peter Bollhorn, 2016