Sarrus linkage

A Sarrus linkage is like a toy that moves in a certain way when you push or pull on it. Imagine you have three flat pieces of metal that are connected in a zig-zag shape. They look kind of like steps going up and down.

You can move the first piece of metal up or down, and this makes the other two pieces move in a certain way. When you move the first piece up, the second piece moves to the left, and the third piece moves up. If you move the first piece down, the second piece moves to the right, and the third piece moves down.

This is called a Sarrus linkage because it was named after a guy named Pierre Sarrus. He was a French mathematician and engineer who figured out how to use this type of linkage in machines like engines and cranes.

Even though the Sarrus linkage looks pretty simple, it's actually really important in the world of machines and engineering. It helps things move smoothly and efficiently, and it's even used in some robots!