Video lessons for Edexcel A Level Old Maths The Trapezium Rule. 1 lesson matched to the Edexcel A Level Old Maths (9371) specification, each working through the content and then applying it to exam-style questions in Unit exams C1, C2, C3 and C4 plus two applied units (e.g. S1 and M1) format. Suitable for A Level Old Maths.