Consider the coordinate plane:
1. The origin is the point where Sharon and Jacob started - (0,0).
2. North - positive y-direction, south - negetive y-direction.
3. East - positive x-direction, west - negative x-direction.
Then,
- if Jacob walked 3 m north and then 4 m west, the point where he is now has coordinates (-4,3);
- if Sharon walked 5 m south and 12 m east, the point where she is now has coordinates (12,-5).
The distance between two points with coordinates
and
can be calculated using formula

Therefore, the distance between Jacob and Sharon is

The intersection between the curves are
3, 0
0, 3
The volume of the solids is obtained by
V = ∫ π [ (4 - (y-1)²)² - (3 - y)²] dy with limits from 0 to 3
The volume is
V = 108π/5 or 67.86
The problem is modelled in the diagram below
Question 1:
The largest area of the pool is half of the area of the circle
Area of circle = πr², where r is the radius given by 1/2 of the diameter
Area of circle = π(60)² = 11309.73355 feet
Area of half of the circle is 11309.73355/2 = 5654.866... ≈ 5654.87 feet (2dp)
Question b:
The area of the pool is the area of the circle subtracts the area of the triangle.
The area of the circle is 11309.73²
The area of the triangle is 1/2 (60×103.92) = 3117.6 feet²
The area of the pool is 11309.73 - 3117.6 = 7922.13 feet²
The volume of the pool = 7922.13 × 4 = 31688.52 feet³
Note: there isn't any information on the fish tank part so the answer above is assumed for the whole pool.