<Tr> <Th> Area </Th> <Td> a + b 2 h (\ displaystyle (\ tfrac (a + b) (2)) h) </Td> </Tr> <Tr> <Th> Properties </Th> <Td> convex </Td> </Tr> <P> In Euclidean geometry, a convex quadrilateral with at least one pair of parallel sides is referred to as a trapezoid (/ ˈtræpəzɔɪd /) in American and Canadian English but as a trapezium (/ trəˈpiːziəm /) in English outside North America . The parallel sides are called the bases of the trapezoid and the other two sides are called the legs or the lateral sides (if they are not parallel; otherwise there are two pairs of bases). A scalene trapezoid is a trapezoid with no sides of equal measure, in contrast to the special cases below . </P> <P> The term trapezium has been in use in English since 1570, from Late Latin trapezium, from Greek τραπέζιον (trapézion), literally "a little table", a diminutive of τράπεζα (trápeza), "a table", itself from τετράς (tetrás), "four" + πέζα (péza), "a foot; end, border, edge". </P>

When can a quadrilateral also be called a trapezoid