I learning how to use this just ignore what I’m saying right now

So from this information we can infer that you are just checking out this website and trying it out for the first time. We have to multiply this by 5. Then divide it by two. And you get your answer, -234,567,876,543,467,890.

The area of a rectangle is equal to length times width.

Mathematically, .

We can arbitrarily choose one expression for length and one for width; the result is the same.

Let's say that  cm is the length, and  cm is the width.

We simply write .

I am assuming you did not mean to write  for the first dimension.