math
Also: the letter "A" has an acute angle. Be Careful What You Measure The smaller angle is an Obtuse Angle , but the larger angle is a Reflex Angle So when naming the angles make sure that you know which angle is being asked for ! Positive and Negative Angles When measuring from a line: a positive angle goes counterclockwise (opposite direction that clocks go) a negative angle goes clockwise Example: −67° Parts of an Angle The corner point of an angle is called the vertex And the two straight sides are called arms The angle is the amount of turn between each arm. How to Label Angles There are two main ways to label angles: 1. give the angle a name, usually a lower-case letter like a or b , or sometimes a Greek letter like α (alpha) or θ (theta) 2. or by t...