4. Kepler's second law helps to determine the ratio between Pluto's velocity at aphelion and perihelion (Veve). To determine this ratio, first calculate the area swept out by Pluto's orbit. This area is approximately equal to the area of a triangle: Area = 0.5(distance to the Sun) current velocity x time. If the area that the orbit sweeps out in a fixed amount of time, such as 30 days, is the same at aphelion and perihelion, this relationship can be written: