How can this be true? Have a look at the picture. All the lines are straight the shapes that make up the top picture are the same as the ones in the bottom picture so where does the gap come from?
Solution to Solid Square
An officer wishing to arrange his men in a solid square found by his first arrangement that he had 39 men left over. He then started increasing the number of men on a side by one but found that 50 additional men would be needed to complete a new square. How many men did the officer have?