Exploring Diagonals

row of dominos

Move the top right-hand corner of the rectangle to see what happens. 



Can you work out what the purple number represents?


Here are some questions you might like to consider:

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

Given the coordinates of the top right-hand corner of the rectangle, is there a quick way to work out the purple number?

What other interesting questions are there to explore?