This is the method of similitude, a geometric version of false position. The figure on page 157 of Volume 1 shows how this is done for a triangle. For the quadrilateral in the exam, locating the small square on the right-hand end of the base, drawing the diagonal up to the left, and noting the point where that diagonal hits the left side of the quadrilateral will produce the desired square. Describe some high points in the history of computation, from scratches and grunts up to the present time. Note that the question asks about the history of computation, which is not the same thing as the history of mathematics.
Computation involves numbers.
The invention of rational numbers. The realization of the existence of irrational numbers. Hindu-Arabic numeral system. Place system, base 10, with 0. Hindu-Arabic algorithms for calculations.