Interior and Exterior Angles Worksheets

What Are Interior & Exterior Angles? Sometimes all you need to put the pieces together is just a little knowledge of basic mathematics angles. Interior and exterior angles are one of the basic angles that students need to know to develop their knowledge of algebra. An angle that is inside a shape is known as an interior angle. Since, triangles have three sides, there can only be three interior angels. It is important to note that the sum of three interior angles a + b + c is always equal to 180 degrees. Let's say a triangle has given two values with the third one unknown; a = 40 degrees, b = 60 degrees, and c =? You can easily find the value by forming the equation a + b + c = 180; 40 + 60 + c =180. On the other hand, an exterior angle lies outside of any shape or an angle that if formed between two shape. It is an angle formed any side of the shape. They are called the supplementary angles, which means that when you add them, they will also be equal to 180 degrees.