May 12, 2015

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.

Teacher and Student versions of full lesson from engageNY

- Mathematics > General
- Mathematics > Geometry

- Grade 9
- Grade 10

Reason abstractly and quantitatively.

Construct viable arguments and critique the reasoning of others.

Use appropriate tools strategically.

Attend to precision.

Look for and make use of structure.

Prove theorems about lines and angles.