1. The document presents a lesson plan for teaching students how to calculate the area of a trapezium.
2. It defines a trapezium as a quadrilateral with one pair of parallel sides and provides the formula to calculate the area as half the product of the distance between the parallel sides and the sum of the lengths of the parallel sides.
3. The lesson plan outlines checking prior knowledge, presenting a model and example calculation, having students derive the formula, and providing practice problems for students to apply the formula to find the area of different trapeziums.