Bienaymé's identity

Bienaymé's identity is a mathematical equation. It is used to help find the area of any shape by breaking it down into smaller shapes and then adding up their areas to find the total area. To do this, you first need to draw a simple grid on the shape and then divide it up into squares or rectangles. Then you can use Bienaymé's identity to figure out the area of each individual square or rectangle. By adding up all these areas, you can get the total area of the shape.