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

Is the angle m p q greater or less than the right angle m p r?

Then it is called an acute angle.

An acute angle is one which is less than a right angle.

Read four acute angles whose vertices are at p.

Acute means sharp.

Why is r p s an acute angle?

What is an acute angle?

OBTUSE ANGLES.

Is the angle m p s greater or less than the right angle m p r?

Then it is called an obtuse angle.