...angles thus formed are equal to one another, each of these angles is a right angle. When two straight lines form a right angle they are said to be perpendicular to one another. Let us suppose the sides of a right angle to be movable, like the legs of a pair of compasses....

...one-half right angles to his right? Lessen 19. 1. Define perpendicular lines and oblique lines. If two lines form a right angle, they are said to be perpendicular to each other ; if they form any other angle, they are said to be oblique to each other. Abbreviation: The sign _L...

...one-half right angles to his right? Lesson 19. 1. Define perpendicular lines and oblique lines. If two lines form a right angle, they are said to be perpendicular to each other ; if they form any other angle, they are said to be oblique to each other. Abbreviation : The sign...