half x (sum of parallel sides) x the difference between them.
A trapezium is a quadrilateral (a shape with four sides) with two of its sides parallel. It is not spelt trapezuim, but rather trapezium. Trapezium is another name for trapezoid.
trapezuim ulnal radois
4 Lines of symmetry
Normally none, but they can have 2 or three.
Of course - a trapezium is a quadrilateral.
She developed arthritis in her trapezium bone in the wrist.
1/2*(sum of parallel sides)*height*length cubic units