Question 1160594
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In general case ---  there is NO way.


To get some estimations, it requires to make some assumptions.



For example, if both shapes are polygons (convex polygons), then there are analytical formulas for their areas 

via the coordinates of their vertices.


Knowing the areas for each, you may find the area in between by subtraction.



In other case, if the outer shape is a narrow strip of uniform thickness around the inner shape, 
then the area of this strip is its width multiplied by the half the sum of the perimeters of the shapes.