In my country, for many years, trapezoid is defined as such in the textbooks:
a quadrilateral with only two parallel sides.
But today, referring to foreign sources, someone told me that:
a quadrilateral with at least two parallel sides.
Wikipedia uses a similar definition. I want to know that does it make sense for a trapezoid to have more than one pair of parallel sides? Does it make sense for a quadrilateral to have for example, three parallel sides? What's wrong with the former definition?