Solution Diagram

It is given that the orbital path of earth around the sun is an ellipse:

      
where e is the eccentricity and a is the major axis distance.

From the diagram, it is shown that the perihelion distance can be obtain by setting θ to 180^o, which yields

For θ = 0, the aphelion distance can be determined:

For the orbit of earth around the sun, the eccentricity is 0.02 and the major axis distance is 3 x 10⁸ km. Hence, the perihelion and aphelion distances are given respectively by

     r_min = a(1 - e) = (3 x 10⁸ km)(1 - 0.02)
            = 2.94 x 10⁸ km

     r_max = a(1 + e) = (3 x 10⁸ km)(1 + 0.02)
            = 3.06 x 10⁸ km