The long tetragon and the two kinds of rhombus
Definition of the rectangle; the rhombus derived from square and rectangle
Folio 2r defines the long tetragon - a rectangle - as a four-sided figure with four right angles whose adjacent sides may be unequal even though its opposite sides are equal. It then treats the rhombus as being of two sorts, one arising from the square and one from the long tetragon. Figures of a long rectangle, a rhombus and a rhomboid accompany the definitions.
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Definition of the long tetragon (rectangle)
The long tetragon is a plane figure contained by four sides with four right angles; though its opposite sides are equal, the sides meeting at a right angle need not be equal to one another.
The rhombus in two sorts
The rhombus is of two kinds: one arising from the square, the other from the long tetragon. Its opposite angles and all its sides are equal, differing only in that each side ends in an acute and an obtuse angle rather than in equal angles.