Plane and solid analytic geometry, by William F. Osgood and William C. Graustein.

X CONTENTS
ART. PAGE
9. Area of a Triangle........ 43
10. General Theory of Parallels and Perpendiculars. Identical
Lines.......... 44
11. Second Method of Finding Parallels and Perpendiculars. 47
Exercises on Chapter II....... 49
CHAPTER III
APPLICATIONS
1. Certain General Methods....... 53
2. The Medians of a Triangle....... 54
3. Continuation. The General Case..... 56
4. The Altitudes of a Triangle....... 58
5. The Perpendicular Bisectors of the Sides of a Triangle. 60
6. Three Points on a Line....... 60
Exercises on Chapter III...... 61
CHAPTER IV
THE CIRCLE
1. Equation of the Circle........ 65
2. A Second Form of the Equation. 66
3. Tangents.......... 69
4. Circle through Three Points...... 72
Exercises on Chapter IV....... 74
CHAPTER V
INTRODUCTORY PROBLEMS IN LOCI. SYMMETRY OF
CURVES
1. Locus Problems......... 79
2. Symmetry.......... 83
Exercises on Chapter V....... 86
CHAPTER VI
THE PARABOLA
1. Definition.......... 88
2. Equation of the Parabola... 90
3. Tangents........ 93