1. The problem statement, all variables and given/known data I have to prove that A1=A2, or the fact that planets will sweep out equal areas in equal amounts of time. The planet I have to do this for is Pluto. Basically, I need help finding the area it "sweeps out" over any length of time of my choosing. 2. Relevant equations major axis = 11.8 x 10^9 km eccentricity = .25 minimum orbital velocity = 3.7 km/s 3. The attempt at a solution So far, I've found the distance of the perihelion and the aphelion. To do this I did: eccentricity = distance b/w foci / major axis then i solved for the foci by doing: dis b/w foci = .25 * 11.8e9 that gave me the distance between the foci, so I was able to find out that the perihelion is 4425000000 km away and the aphelion is 7375000000 km. Now do I just make a triangle for each with the legs being the distance away and the other being time traveled. It's hard to explain, but this picture shows it well: http://outreach.atnf.csiro.au/education/senior/cosmicengine/images/cosmoimg/kepler2ndlaw.gif [Broken] So basically, how do I prove that those two areas equal with the info I now have Any help would be appreciated.