To place at a given point (as an extremity) a straight line equal to a given straight line. • Start with the point A and line segment BC. • Connect point A to point B. • Construct the equilateral triangle DAB on line AB (see Proposition 1). • Extend line DA to create line AE, and extend line DB to create line BF. • Create the circle CGH around point B with a radius of BC. • Create the circle GKL around point D with a radius of DG. The line AL has been created equal to the given straight line BC from point A.