Henry Ernest Dudeney/Puzzles and Curious Problems/168 - Mental Arithmetic/Solution

by : $168$

 * Mental Arithmetic

Solution
gives $3$ and $5$:


 * $3^2 + 3 \times 5 + 5^2 = 49 = 7^2$

but we also have:
 * $7^2 + 7 \times 8 + 8^2 = 169 = 13^2$