153394

This is the answer to the 1st question :)

When you put the quadrilateral and triangle from the 8 by 8 square together they have a gap between them, they don't properly join up. When you draw the second 13 by 5 rectangle, you draw what you think, which is 3cm, but you were meant to draw 3 1/13. This is because 5/13 = x/8, so x= 40/13, which is 3 1/13
If you do this instead, you will find that it works!!!