Trigonometry can be used to find the length of a side in a triangle. Trigonometry close trigonometryThe study of sides and angles in triangles. can be used to find a missing side in a right-angled ...

The triangles’ sides are these lengths because they obey Pythagoras’s theorem: the square of the longest side is equal to the sum of the squares of the other two sides.

In it, the students fill one larger triangle with an infinite sequence of smaller triangles and use calculus to find the lengths of the larger triangle’s sides.

It is shown how a triangle can be recognised from the odd moments of the length of random chords and how a quadrilateral can be recognised from the derivative of its chord length density. Journal ...