“My God!” said Cruikshank in despair.
But I acceded her the little curly bits. She had grasped the shape of a triangle.
“Well, try and forget the curly bits,” said I. “They have three sides—haven’t they?”
She acquiesced.
“Like this,” I went on hurriedly, and, dragging out my pencil again, I drew a triangle on a piece of paper.
“That’s it,” said she; “but they don’t meet at the top.”
“Some do,” I replied; “the ones that Euclid made did.”
“Well, go on,” she said, with greater interest. “What’s an equitriangle?”
“An equilateral triangle,” said Cruikshank, now stepping in when I had done all the hard work for him, “is a triangle which has all its sides of equal length. That side,”—he pointed to my drawing—“that side and that side all equal. Now Euclid’ll show you,” he continued, “how to construct an equilateral triangle on a given finite straight line. You needn’t measure anything. You only want a compass to make a couple of circles, and he’ll prove to your reason that all the lines of that triangle are one and the same length as this line you see on the paper now.”