standard_description: Prove theorems about triangles. Theorems include: measures of interior angles of a triangle sum to 180°; base angles of isosceles triangles are congruent; the segment joining midpoints of two sides of a triangle is parallel to the third side and half the length; the medians of a triangle meet at a point.
problem_activity: Problem 1
Find all the angle measures that equal 127° and all the angle measures that are supplementary to 127°.
[IMG]
Problem 2
In the figure,
$${\overline{AB} \parallel \overline{CD}}$$
and
$${\overline{EF} \parallel \overline{GH}}$$
. Prove that
$${\angle AFE \cong \angle DKH}$$
.
[IMG]


aligns: no