Who should attend. The course is designed for those who may have to conduct or participate in an aircraft accident investigation. This may be in the role of official investigator for a State or as an accredited representative/technical advisor of a manufacturer, operator or service provider.
Before electronic calculators, converting square varas (at 1 vara = 32.8748 inches) to acres was a tedious job. But if 1 vara = 33 1/3 inches, 3 varas are exactly 100 inches, 36 varas are exactly 100 feet, and 108 varas are exactly 100 yards. An easy division and some shuffling of the decimal point do the job.
There are 27,878,400 square feet in a square mile. That is the correct amount because to find the area of something, one multiplys the length and width. So to find how many square feet are in a square mile, one must multiply 5,280(the amount of feet in a mile) times 5,280(the product is 27,878,400). I hope that answers your question :)