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

Read the interior opposite angles on the right of the intersecting line e f.

On the left of it. On the right of r s. On the left.

Read the interior alternate angles formed by the lines a b, c d, and e f.

Which pair are acute angles?

Which pair are obtuse angles?

Why are b m n, m n c, interior angles? Why alternate? What are alternate angles?

Read the exterior alternate angles of the same lines.

Read the acute interior alternate angles of the parallels t u, v w. The obtuse.

The acute exterior alternate angles. Obtuse.

Read the pair of opposite exterior angles on the right of the line e f. On the left.