For this type of work you could use geometric solving, there are many example in all the equal area subjects.
The idea there is to make lines from angleMin to angleMax (covering the rectangle) measure the surface between each pair of line then represent as a curve the angle in abcissa and cummulative area as ordinates.
The draw lines equally spaced in area, find the intersection in the curves => you have the angles that could lead to equal area division.
1 Like