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Tutorial

- Students know that corresponding angles, alternate interior angles, and alternate exterior angles of parallel lines are equal. Students know that when these pairs of angles are equal, then lines are parallel.
- Students know that corresponding angles of parallel lines are equal because of properties related to translation. Students know that alternate interior angles of parallel lines are equal because of properties related to rotation.
- Students present informal arguments to draw conclusions about angles formed when parallel lines are cut by a transversal.

Angles that are on the same side of the transversal in the same positions are called corresponding angles.

Corresponding angles are the exact same size in degree measurement.

When angles are on opposite sides of the transversal and between (inside) the parallel lines, they are called alternate interior angles.

When angles are on opposite sides of the transversal and outside of the parallel lines (above and below the two parallel lines), they are called alternate exterior angles.

Adjacent angles are angles that are next to each other. In several of the examples that we are going to see in this lesson, adjacent angles will be supplementary - meaning that when they are added together they equal 180 degrees.

Vertical Angles are angles that are across from one another diagonally. They are the SAME degree angle.

Below is the student copy of Lesson 12.

Below is the NYS Common Core Teacher Copy of Lesson 12.