Page:The Mathematical Principles of Natural Philosophy - 1729 - Volume 1.djvu/202

 whoe given part DF is to be interpoed between the right lines AB, AC given poition; then by applying the preceding contruction to this cae, the problem will be olved.

To decribe a trajectory given both in kind and magnitude, given parts of which hall be interpoed berween three right lines given by poition. (Pl. 12. Fig. 3.)

Suppoe a trajectory is to be decribed that may be imilar and equal to the curve line DEF, and may be cut by three rights lines AB, AC, BC, given by poition, into parts DE and EF, imilar and equal to the given parts of this curve line.

Draw the right lines DE, EF, DF; and place the angles D, E, F, of this triangle DEF, o as to touch thoe right lines given by poition (by lem. 26). Then about the triangle decribe the trajectory, imilar and equal to curve DEF. Q. E. F.