standard_description: Know precise definitions of angle, circle, perpendicular line, parallel line, and line segment, based on the undefined notions of point, line, distance along a line, and distance around a circular arc.
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