Saturn takes 17.6 more years than Jupiter, so 17.6 + 11.9 will get you how long Saturn will take to orbit the sun, which would give you 29.5 years.
The slope of line T is -1/5, because perpendicular lines have opposite reciprocal slopes, meaning the opposite sign (positive or negative) and flipped (whole number becomes a fraction).
Here it is given that the width is x ft and total length of the fence is 2400 ft .
Let the length be y ft
So we have

Let A represents area, and area is the product of length and width .
So we get

Substituting the value of y, we will get

Second part
The area is maximum at the vertex, and vertex is

And

And that's the required dimensions .