The homothety is a transformation of space which dilates distance with respect to a fixed point O called the origin. The similitude ratio k is the number by which distances are multiplied. This ratio can be set to negative values as well.
All objects in the animation can be moved with a simple “click and drag”. The ratio k can be altered by clicking on the ratio and directly entering a new value.
Select an object then drag it around the plane.
Click and drag the origin O.