Question

How to find the side length of a rhombus with its diagonals?

Answer 1

In the picture below, you can see a rhombus with its diagonals bisecting themselves. The red triangle has a right angle. Using Pythagorean theorem, you calculate the side of rhombus BC like this:

BC2=CO2+BO2

BC2=(AC2)2+(BD2)2

BC=(AC2)2+(BD2)2−−−−−−−−−−−−√

where AC and BD are lengths of diagonals.