Go to the command area and enable option justify with the command oj+ or toggle it on with the Alt–j key combination. In the text area, append the following lines.
Prince Humperdinck was shaped like a barrel. His chest was a great barrel chest, his thighs mighty barrel thighs. He was not tall but he weighed close to 250 pounds, brick hard. He walked like a crab, side to side, and probably if he had wanted to be a ballet dancer, he would have been doomed to a miserable life of endless frustration.
You will find that the editor automatically justifies each line with your right margin when it fills. This option is only active when option fill is enabled.