Try to fill in the missing information correctly in the boxes.
Every step you do in the worksheet you have to calculate on your own too. At the end you can compare your solution with the one of the worksheet.
Find the point C of the parallelogramm and calculate the area of it.
A=(1, 1); B=(9, 1); D=(3, 4.5)

If you think you made a mistake, you can compare your work with the worksheet. If the worksheet is incorrect too you have an error in reasoning, if only the numbers are wrong, you did a calculation error.
Use this help to correct your exercise.