They struck at the staves of the sarissae, but the cavalry in the rear embarrassed their attack; and the phalanx, supported by the elephants, lengthened and contracted, presenting itself in the form of a square, a cone, a rhombus, a trapezium, a pyramid.
"Salammbo"
Gustave Flaubert
To prove to them that it is necessary to mention the right angles in describing a square, you can make a rhombus, and show them its different shape with its acute and obtuse angles.
"Guide to the Kindergarten and Intermediate Class and Moral Culture of Infancy."
Elizabeth P. Peabody Mary Mann
What is the difference between a square and a rhombus?
"Guide to the Kindergarten and Intermediate Class and Moral Culture of Infancy."
Elizabeth P. Peabody Mary Mann