1. Euclidian Mathematics
Spiro Stilianoudakis Geometry 9th Grade

2. Euclid Lived in the region of Alexandria during 300 BC
Coined the term “Euclidian Plane” where angles are made
Specialized in conic sections
“Father of Geometry”
Greek mathematician
Known for the construction of many mathematical proofs related to geometry

3. Types of Angles alternate-exterior angles alternate-interior angles
same-side interior angles
corresponding angles

4. Alternate-Exterior Angles
Alternate Exterior Angles are created where a transversal crosses two (usually parallel) lines. Each pair of these angles are outside the parallel lines, and on opposite sides of the transversal.
In the figure to the right, the alternate exterior angles are the angles labeled 1, 2, 3, and 4

5. Alternate-Interior Angles
Alternate Interior Angles are created where a transversal crosses two (usually parallel) lines. Each pair of these angles are inside the parallel lines, and on opposite sides of the transversal.
In the figure to the left, the alternate interior angles are the angles labeled 5, 6, 7, and 8.

6. Same-Side Interior Angles
Created where a transversal crosses two (usually parallel) lines. Each pair of same-side interior angles are inside the parallel lines, and on the same side of the transversal.
In the figure to the right, the same side interior angles are the angles labeled 3, 4, 5, and 6.

7. Same-Side Exterior Angles
Created where a transversal crosses two (usually parallel) lines. Each pair of same-side exterior angles are inside the parallel lines, and on the same side of the transversal.
In the figure to the left, the same side exterior angles are the angles labeled 1, 2, 7, and 8.

8. Corresponding Angles
Corresponding angles are created where a transversal crosses other (usually parallel) lines. The corresponding angles are the ones at the same location at each intersection.
An example of corresponding angles in the figure to the right are the angles labeled 1 and 5.