The Peaucellier Linkage

This is a famous linkage originally invented in order to convert rotary motion to

straight-line motion.

As the black segment OP rotates through the angle from to , the

opposite vertex Q of the red parallelogram moves along a segment of

the -axis:

> CP:=animate({LOA,LOP},theta=Pi/4..Pi,color=black,scaling=constrained):

> PP:=animate({LPR,LPS,LQR,LQS},theta=Pi/4..Pi,color=red,scaling=constrained):

> MP:=animate({LAR,LAS},theta=Pi/4..Pi,color=blue,scaling=constrained):

> display({CP,PP,MP});

Computations