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

Name a hexagon that is not regular.

Name a regular hexagon.

A regular octagon. A regular heptagon.

A polygon is a plane figure bounded by straight lines.

LESSON TWENTIETH.

REVIEW.

Name all the triangles. (Diagram [16].)

Why is Fig. A a triangle?

What is a triangle?