These materials were developed to help high school teachers to become familiar with the approach to tenth-grade Euclidean geometry which was adopted by the School Mathematics Study Group (SMSG). It is emphasized that the materials are unsuitable as a high school textbook. Each document contains material too difficult for most high school students. It is assumed that teachers who study the notes have good backgrounds in axiomatic geometry. In particular, some familiarity with Euclid's Elements is presupposed. Chapters include: (1) Historical Introduction; (2) Logic; (3) Points, Lines, and Planes; (4) Real Numbers and the Ruler Axiom; (5) Separation in Planes and in Space; (6) Angles and the Protractor Postulates; (7) Congruence; (8) Parallelism; (9) Area; and (10) Circles and Spheres. (Author/RH)