MA19.3.23

Mathematics (2019) Grade(s): 3

Students know:

Students are able to:

Make conjectures about the relationships and measurements of the angles created when two parallel lines are cut by a transversal.
Informally prove that the sum of any triangle's interior angles will have the same measure as a straight angle.

Students understand that:

Missing angle measurements can be found when given just one angle measurement along a transversal cutting through parallel lines.
Every exterior angle is supplementary to its adjacent interior angle.
Parallel lines cut by a transversal will yield specific angle relationships that are connected to the concepts of rigid transformations (i.e. vertical angles are reflections over a point. corresponding angles can be viewed as translations).
The sum of the interior angles of a triangle is 180 degrees.