Marks' first lessons in geometry / In two parts. Objectively presented, and designed for the use of primary classes in grammar schools, academies, etc.

by Bernhard Marks

If a triangle has its three sides equal to each other, what do you call it?

Then when a rhomboid has its sides equal to each other, what may it be called?

An equilateral rhomboid is called a rhombus.

A rhombus is an equilateral rhomboid.

See Note [D], Appendix.

Name two other rhombuses, or rhombs.

What four names can you give to Fig. e h?

Why a quadrilateral? Why a parallelogram? Why a rhomboid? Why a rhombus?

RECTANGLES.

Has the parallelogram i l any right angles?