Geometry Review

​Adjacent Angles

are two angles that are side by side and share a common vertex and a common side, however, they do not overlap. They are often formed by intersecting lines or line segments.

​Vertical angles 

​are angles that are on the opposite sides of two lines that intersect. In the figure below, angle a and angle b are vertical angles.

​Complement Angles

​of the two angles are decided by the sum of their measurement. two angles that add up to 90 degrees. They can be adjacent angles or not adjacent angles. Adjacent complementary angles make a right angle.

Supplementary Angels​

​are two angles that add up to 180 degrees. They can be adjacent or not adjacent. Adjacent supplementary angles make a straight line.

​Angles in parallel lines are angles that are created when two parallel lines are intersected by another line called a transversal.

​Corresponding Angles

​Corresponding angles are one of the types of angles that are formed when two parallel lines are intersected by the transversal. Then the corresponding angles are congruent (equal).

​Alternate angles

​Alternate angles in parallel lines are angles that occur on opposite sides of the transversal line and have the same size. Sometimes called ‘Z angles’.

​There are two different types of alternate angles, alternate interior angles and alternate exterior angles. 

​Alternate interior angles:

Here, the two angles of a and b are in between the parallel lines and therefore are pairs of alternate interior angles.

​Alternate exterior angles:

Here, the two angles of c and d are outside of the parallel lines and so these are two examples of pairs of alternate exterior angles.

Consecutive Interior Angles

​These are pairs of angles that are formed when a transversal line crosses two parallel or non-parallel lines. Consecutive interior angles also known as co-interior angles lie on one side of the transversal but inside of the two lines. The pair of consecutive interior angles add up to 180°

​Parallel and Perpendicular Line