Ex. 2. What is the area of the parabolic frustum, whose two ends are 6 and 10, and its altitude 3?Ans. 24½.PROBLEM XI. To Construct or Describe an Hyperbola.Let D be the cen∣ter of the hyper∣bola, or the middle of the transverse AB; and BC perpen∣dicular to AB, and equal to half the conjugate.With center D, and radius DC, de∣scribe an arc meet∣ing AB produced in F and f, which are the two focus points of the hyperbola.diagramThen, assuming several points E in the transverse produced, with the radii AF, BE, and centers f, r, de∣scribe arcs intersecting in the several points G; through all which points draw the hyperbolic curve.PROBLEM XII. In an Hyperbola to find the Transverse, or Conjugate, or Ordinate, or Absciss.CASE I. To find the Ordinate.As the transverse∶Is to the conjugate∷So is the mean propor. between the two abscisses∶To the ordinate.0