# Sqaure in square

Author: mathforces
Problem has been solved: 39 times

Русский язык | English Language

The square $EFGH$ is located inside another square $ABCD$ as shown on the picture below. It is known that $AH = 1$, $BE = 2$, $CF = 3$. The length of the segment $DG$ is representable as $\sqrt {a}$ for some natural number $a$. What is $a (a-1)$ equal to?