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 ...

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 ...

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.