Question; Prove Proposition 2.2.7

30 Chapter 2 Euclidean Rigid Motions P Thus, An . Pm and RA,2a agree on the point P. Since it is easy to find three such noncollinear points P, it follows from Theorem 2.1.3 that An . Am and RA,2a are identical. Q.E.D. Proposition 2.2.7 Let m and n be two parallel straight lines. Let AB be a line segment that first intersects m and then n, that is perpendicular to both m and n, and whose length is twice the distance between m and n. Then, Pn 0 Pm = TAB. Prove proposition 2.2.7