In the following diagram, ABCD form a trapezium. Given that coordinates of E is (U, 4) and coordinates of C is {5, 1). A53 is a straight line and perpendicular to line BC. Given that gradient of line AB is l . Write down the equations of line AB and line BC. Hence, using these two equations, nd the coordinates of B. If E is the midpoint of line AB, determine the coordinates of A. (u