TY  - BOOK
AU  - Clemens,C.Herbert
TI  - Two-dimensional geometries: a problem-solving approach 
T2  - Pure and applied undergraduate texts 
SN  - 9781470447601  
U1  - 516.154 23
PY  - 2019///
CY  - Providence
PB  - American Mathematical Society
KW  - Γεωμετρία, Περιγραφική
N1  - Περιλαμβάνει βιβλιογραφικές παραπομπές και ευρετήριο.; Introduction -- Neutral geometry. Euclid's postulates for plane geometry -- Euclidean (plane) geometry. Rectangles and cartesian coordinates -- Concurrence and circles in euclidean geometry -- Spherical geometry. Surface area and volume of the R-sphere in euclidean 3-space -- Usual dot product for three-dimensional Euclidean space. Euclidean three-space as a metric space -- Transformations -- K-geometry. Changing coordinates -- Uniform coordinates for the two-dimensional geometries -- Return to spherical geometry. Spherical geometry from an advanced viewpoint -- Hyperbolic geometry. The curvature K becomes negative
ER  -