A page opening from the editio princeps of Archimedes Opera (1544). This is the Greek text of the *Quadrature of the Parabola*, Proposition 16, showing that the area of the parabola is one-third the area of the triangle formed by the base, the tangent, and the line joining the base and tangent, and Proposition 17, that the area of the parabola is four-thirds the triangle with the same base and equal height. Caltech Library.