standard_description: Prove theorems about triangles. Theorems include: a line parallel to one side of a triangle divides the other two proportionally, and conversely; the Pythagorean Theorem proved using triangle similarity.
problem_activity: Identify whether the following statements are true or false.
a.   A parallelogram is always a trapezoid. T / F
b.   A quadrilateral is always a parallelogram. T / F
c.   A parallelogram is always a polygon. T / F


aligns: no