**Topic**: Finding Unknown angles

**Key Vocabulary:** **1.** Supplementary Angles : Two Angles are Supplementary when they add up to 180 degrees.

**2.** Complementary angles: Two Angles are Complementary when they add up to 90 degrees (a Right Angle).

**3.** Vertical angles: Vertical Angles are the angles opposite each other when two lines cross. They are always equal.

**4.** Adjacent Angles: Two Angles are Adjacent when they have a common side and a common vertex (corner point), and don’t overlap.

**Prior Knowledge:** Students should already have a clear idea about ( Acute, Obtuse, Reflex) angles and their measurement. In addition, they should also have had clear idea about the parts of a angle such as (The corner point of an angle is called the **vertex) **and ( the two straight sides are called **arms) **and how to give the angle a name, such as ABC or CBD