This numerical sequence corresponds to a<u> geometric progression</u>, which occurs when there is a multiplication of the sequence numbers for a common reason whose result will always be the successor number of the numerical sequence.
Like for example:
3,6,12,24,48
The common reason for the geometric progression is the number 2, so the first term of the sequence multiplied by 2 will be equal to the second term of the sequence and so on:
3x2 = 6
6x2 = 12
12x2 = 24
24x2 = 48
It is necessary to emphasize that the ratio of a geometric progression will always be constant and will always be a number other than zero.
We can use the formula for area of a triangle to solve this problem A = (1/2)ab where a is the altitude or height and b is the base also we know that a = 4b in this problem and we know that A = 18 sq ft so 18 = (1/2)(4b)b 18 = 2b2 9 = b2 b = 3 so the base is 3 and the height is 4 times that a = 4(3) = 12 (height of the sail Hope this helps