Exploring diagonals

Move the corner of the rectangle. Can you work out what the purple number represents?

Problem





Move the top right-hand corner of the rectangle.

Can you work out what the purple number represents?



What would be the dimensions of a rectangle with a purple number of 24? Is there more than one?

If I tell you the coordinates, can you find a quick way to work out the purple number?

What other interesting questions might you explore?