Semi major axis - planetary Science

[hhhp8cec1]

Homework Statement

A comet with a perihelion distance of d = 1.242 is currently 211(degrees) from pericenter, and 4.499 AU from the Sun. Compute the semi-major axis a of this comet’s orbit.

Homework Equations

P(^2) = a^3

The Attempt at a Solution

I tried to use Kepler's third law but I don't know how to find the period, P.
I think that is not the right way to approach this problem...

Any help would be appreciated, thank you [/B]

 

[gneill]

You'll need to search your notes and textbook for other formulas that include the given variables.

You should be able to use a bit of reasoning from the given data to determine what type of conic section the comet orbit must have.