Measured by, 208 Memorizing, 12, 79 Menaechmus, 33, 316 Menelaus, 35 Meray, 67, 68, 196, 289 Methods, 41, 42, 115 Metius, 279 Mikami, 264 Minchin, 14 Models, 93, 290 Modern geometry, 38 Mohammed ibn Musa, 37 Moore, E. H., 131 Mosaics, 274 Mueller, H., 68 Muensterberg, 22 Napoleon, 24, 287 Newton, 24 Nicomedes, 34, 215 Octant, 242 Oenopides, 31, 212, 216 Optical illusions, 100 Oughtred, 37 Paciuolo, 86 Pamphilius, 185 Pappus, 36, 230, 263 Parallelepiped, 303 Parallels, 149, 181 Parquetry, 222, 274 Pascal, 24, 159 Peletier, 169 Perigon, 151 Perry, J., 13, 14 Petersen, 164 Philippus of Mende, 32, 185 Philo, 178 Philolaus, 309 [pi], 26, 27, 34, 36, 271, 278, 280 Plane, 140 Plato, 25, 31, 41, 48, 129, 136, 137, 309, 310 Playfair, 128 Pleasure of geometry, 16 Plimpton, G. A., 51, 52 Plutarch, 259 Poinsot, 311 Point, 135 Polygons, 156, 252, 269, 274 Polyhedrons, 301, 303, 310 Pomodoro, 179 _Pons asinorum_, 174, 265 Posidonius, 128, 149 Postulates, 31, 41, 116, 125, 292 Practical geometry, 3, 7, 9, 44 Printing, effect of, 44 Prism, 303 Problems, applied, 75, 103, 178, 186, 192, 195, 203, 204, 209, 215, 217, 242, 267, 295, 317 Proclus, 36, 47, 48, 52, 71, 127, 128, 136, 137, 139, 140, 149, 155, 186, 188, 197, 212, 214, 253, 258, 310, 311 Projections, 300 Proofs in full, 79 Proportion, 32, 227 Psychology, 12, 20 Ptolemy, C., 35, 278; king, 48, 49 Pyramid, 307 Pythagoras, 29, 40, 258, 272, 273, 310 Pythagorean Theorem, 28, 36, 258 Pythagorean numbers, 32, 36, 263, 266 Pythagoreans, 136, 137, 185, 227, 269, 309 Quadrant, 236 Quadratrix, 31, 215 Quadrilaterals, 148, 157 Quadrivium, 42 Questions at issue, 3 Rabelais, 24 Radius, 153 Ratio, 205, 227 Real problem defined, 75, 103 Reasons for studying geometry, 7, 100 Rebiere, 25 Reciprocal propositions, 173 Recitation in geometry, 113 Recorde, 37 Rectilinear figures, 146 Reductio ad absurdum, 41, 177 Regular polygons, 269 "Rhind Papyrus," 27 Rhombus and rhomboid, 148 Riccardi, 47 Richter, 279 Roman surveyors, 247 Saccheri, 127 Sacrobosco, 43 San Giovanni, 192 Sauvage, 164 Sayre, 272 Scalene, 147 Schlegel, 68 Schopenhauer, 121, 265 Schotten, 46, 135, 149 Sector, 154, 156 Segment, 154 Semicircle, 146 Shanks, 279 Similar figures, 232 Simon, 38, 56, 135 Simson, 142 Sisam, 11 Smith, D. E., 25, 37, 51, 52, 119, 131, 135, 159 Solid geometry, 289 Speusippus, 32 Sphere, 321 Square on a line, 257 Squaring the circle, 31, 32, 277 Staeckel, 128