I need only part c

Mars orbits the Sun at a mean distance of 228 million km, in a period of 687 days. The Earth orbits at a mean distance of 149.6 million km in a period of 365.26 days. All answers should be in the range (0, 2pi)
a) Suppose Earth and Mars are positioned such that Earth lies on a straight line between Mars and the Sun. Exactly 365.26 days later, when the Earth has completed one orbit, what is the angle between the Earth-Sun line and the Mars-Sun line? (in rad)
b) The initial situation in part a) is a closest approach of Mars to the Earth. What is the time between 2 closest approaches? Assume constant orbital speeds and circular orbits for both Mars and Earth. (Hint: when angles are equal) (in days)
c) Another way of expressing the answer to part (b) is in terms of the angle between the line drawn through the Sun, Earth, and Mars in the two closest approach situations. What is that angle? (in rad)

To determine the angle between the line drawn through the Sun, Earth, and Mars in the two closest approach situations, we need to calculate the angular separation between Mars and Earth at their closest approach.

In part b, we found that the time between two closest approaches is equal to the time it takes Mars to complete one orbit minus the time it takes Earth to complete one orbit. Since Mars takes 687 days to complete one orbit and Earth takes 365.26 days, the time between two closest approaches is:

687 days - 365.26 days = 321.74 days

Now, let's calculate the angle between the line drawn through the Sun, Earth, and Mars at their closest approach.

The angular speed is given by the equation:

angular speed = 2π / period

For Mars, the angular speed is:

angular speed of Mars = 2π / 687 days

For Earth, the angular speed is:

angular speed of Earth = 2π / 365.26 days

To find the angle, we can use the equation:

angle = angular speed * time

For Mars, the angle is:

angle of Mars = (2π / 687 days) * 321.74 days

For Earth, the angle is:

angle of Earth = (2π / 365.26 days) * 321.74 days

Finally, the angle between the line drawn through the Sun, Earth, and Mars at their closest approach can be calculated by subtracting the angle of Earth from the angle of Mars:

angle between the line drawn through the Sun, Earth, and Mars = angle of Mars - angle of Earth

Now, you can substitute the values and calculate the angle in radians.