Three circles are pairwise externally tangent, as shown below. The circles have radii of 1 meter, 3 meters and 5 meters. In square meters, what is the area of the polygon formed by connecting the centers of the circles?
Here's a hint: Note that the lengths of each side are the sum of 2 radii (biggest radii + middle radii; middle radii + smallest radii; biggest radii + smallest radii)
Now, use Heron's to solve for the area.