The second in a series of puzzles involving algebra and/or geometry.
Two circles, with radii of 121 units and 289 units, are contained within a rectangle as shown:

Calculate the area of the rectangle.
Let the characters a, b, …, f equal the digits of the area.
The cache can be found at S41 de.(b-a)(f-d)c E173 (e-b)c.a(a+e)(c+d)
There is parking on the West side of the road about 20m SW of the GZ. Take care with children - there is no footpath and the road is narrow.
The cache contains only a log sheet – bring your own pen.