In the case that your ICA file doesn't open, it is highly likely that you do not have the correct software application installed on your PC to view or edit ICA file extensions. If your PC opens the ICA file, but it's the wrong application, you'll need to change your Windows registry file association settings.
He found the period of the planet's revolution around the Sun in years would be equal to the cube of its average distance from the Sun in astronomical units. Let us suppose we find an asteroid with a perihelion distance of 3 AU, and aphelion distance of 5 AU. Calculate its semimajor axis (average distance from the Sun) and use Kepler's Third Law to find its orbital period in years.
Follow the steps given below. 1  Find the last period start date. 2  Find out shortest and longest period cycles by observing your period cycles for atleast 6 months. 3  Illustrative example of calculating fertile period.  shortest cycle=27 1  days. longest cycle=28 days.  Subtract 18 days from the shortest cycle 27-18=9 days. Subtract 10 days from the longest cycle 28-10=18 days. The 9th day to 18 th day from your last period is the unsafe period. The rest is the safe period.