Why do planets revolve in elliptical orbits and not circular orbits

For any given distance from another body there is exactly one velocity that will put another object in a circular orbit. At the same distance there are an infinite number of velocities that will put another object in an elliptical orbit. Since the planets and their moons

A circular orbit is indeed, a special case of an elliptical orbit, but in the case of the circular orbit the eccentricity (the amount the orbit deviates from a circle) is zero.

Communication satellites are generally placed in what we call circular orbits (at high altitude); however, even with all the tweaking of their orbits as they are put into service they are still very slightly elliptical. It is very difficult, indeed, to get it exactly right, especially over longer time periods. The other celestial bodies in the solar system continually perturb the orbits of even Earth satellites, so if one was placed in an exactly circular orbit it wouldn't stay there for very long.

A circle is merely a special case of an ellipse.

The planetary orbits are the result of the random condensing of dust into the planets, and random collisions. Only the most incredible coincidence would result in a perfectly circular orbit. There are an infinite number of stable elliptical orbits, but only one circular orbit.

Solar systems are chaotic. They form out of condensing clouds of gas and dust, and the various bodies in them interact in a highly complex manner. This makes it highly unlikely for a perfect circle to form. A perfect circular orbit would require highly precise conditions- not likely in the chaotic environment of a new solar system.

Maybe because planets are like us - we prefer to run around stadiums that are elliptical and not circular when it comes to sports.

by kelers law the square of radius is directly proprtional to cube of time takenlto complte 1 revolution

Because they formed imperfectly, somewhat lopsidedly. A circle is just a perfectly symmetrical ellipse.

the same reason why we have tides, planets pull planets and then the planet goes closer or further. at least i think so.

Gravity

Check out Kepler's three laws of planetary motion....Google it, I didn't have time to read the whole thing.

Because they are protestant

the answer to this question was given about 350 years ago, moron!