Related topics: Shapes, patterns, Maths
tra·pe·zi·um /trəˈpiːziəm/ noun [countableC] technical 1. British EnglishBrECF a shape with four sides, only two of which are parallel 梯形 →5 see picture at 见图 shape1
2. American EnglishAmECF a shape with four sides, none of which are parallel 不规则四边形