Angles: Basics

How are angles formed?


Angles are formed when two straight lines intersect with each other and there are several important things that you need to know about the angles that are formed as a result.

Let’s first of all look at naming the various angles based on their size and how they appear:


Standard Methods


When talking about angles, or answering questions on angles it is usual to follow standard methods on how we refer to the angles. If a shape is given and we need to refer to angles in the shape, we use the lettering in the shape to help us clarify exactly which angle we are referring to at any time.

Hence, angle BAC would be the angle as shown, angle ACD as shown, and angle BAD as shown. Notice that we could not just refer to angle “A” as there are three separate angles that can be formed with “A”, BAC, BAD, and CAD.