Mei puts the polygons at right into a bucket and asks Brian to pick one.
What is the probability that he pulls out a quadrilateral with at least one pair of parallel sides?
Identify the shapes that are quadrilaterals with a
Identify the shapes that have parallel sides with a
Write a fraction where the numerator is the number of shapes that have both parallel sides and four sides, and where the denominator is the total number of shapes.
What is the probability that he pulls out a polygon with rotation symmetry?