Suppose the Orbits Are Circular?

We know that the venus distance from the sun is point seven, two times earths sun distance. Vy, kepler's third law. So, going with that nalogy, again, assuming the orbits are circular, right? Bu assuming it, i mean us, right? Ecause technically it is elliptical. But this, these are under pretty harsh assertions, because, like, they're assuming. They're not like, going all wonkey cause in actuality, right? The perigiapages are not, like, very similar. It's not very circular, circular at all. You would probably know the mass of the earth. How would you ido know