Find the area of the trapezium below.
Step 1: Find the length of .
Since is a trapezium, therefore is parallel to .
Any quadrilateral with a pair of parallel sides and 2 right angles must be a rectangle. Therefore, is a rectangle.
Opposite sides of a rectangle are equal in length, so .
Step 2: Find the length of using Pythagoras' theorem.
Step 3: Find the area of .
Step 4: Find the area of rectangle .
Step 5: Find the area of trapezium .