Trigonometry may seem arcane to a new learner, but it is a branch of mathematics rooted in ancient astronomy, and developed over many years by Babylonian, Egyptian (it helped them build the pyramids!), Greek, Indian, and Arab mathematicians before returning to Europe in the 13^th century.

This activity encourages a student to consider all possible side-length ratios in a triangle, and then work out which of the three most important trigonometric ratios, sin, cos or tan, correspond to the ratio of largest value.

The competitive aspect hopefully makes it more fun than a straightforward drill and practice.