Explain what causes the length of the shadow to change during the day.

As the day goes by, the Earth moves. When the Earth moves/rotates, the direction of where the sun is moves too. So in the morning, the sun could be on the right, casting a long shadow to the left, while during noon, the sun is high above, and your shadow is basically underneath you.

Is there a picture of the diagram?

Answer the zagros mountains, stretch across western iran and are located next to the khuzestan plain; answer( zagros mountains