# “Math Vocabulary” – The Language of Mathematics

Learn Math Vocabulary in English through pictures and video.

The language of mathematics is the system used by mathematician to communicate mathematical ideas among themselves. This language consists of a substrate of some natural language (for example English) using technical terms and grammatical conventions that are peculiar to mathematical discourse, supplemented by a highly specialized symbolic notation for mathematical formulas.

Contents

## Learn Mathematics Language through Pictures    ## How to Say and Write Numbers in English   ## “Angles” Vocabulary • An angle equal to 1/4 turn (90° or π/2 radians) is called a right angle. Two lines that form a right angle are said to be normal, orthogonal, or perpendicular.
• A pair of angles opposite each other, formed by two intersecting straight lines that form an “X”-like shape, are called vertical angles or opposite angles or vertically opposite angles.
• Angles larger than a right angle and smaller than a straight angle (between 90° and 180°) are called obtuse angles (“obtuse” meaning “blunt”).
• An angle equal to 1/2 turn (180° or π radians) is called a straight angle.
• Angles larger than a straight angle but less than 1 turn (between 180° and 360°) are called reflex angles.
• An angle equal to 1 turn (360° or 2π radians) is called a full angle, complete angle, or a perigon.
• Angles that are not right angles or a multiple of a right angle are called oblique angles.   Recent comment authors 