S=
(a+b)‧h
2
- S= surface area
- a,b= bases (a,b are parallels - a//b)
- h=height
In Euclidean geometry, a convex quadrilateral with at least one pair of parallel sides is referred to as a trapezoid but as a trapezium in English outside North America. The parallel sides (a//b) 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).