Posts tagged 'trapezium'

G.63 square, oblong, rhombus, and rhomboid

Of quadrilateral figures, a square is equilateral and right-angled; an oblong is right-angled but not equilateral; a rhombus is equilateral but not right-angled; a rhomboid has opposite sides and angles equal but is neither equilateral nor right-angled.

G.64 parallelograms on the same base in the same parallels

Parallelograms on the same base and in the same parallels are equal in area.