00275    a2200109   4500020001500000082001500015245003300030260004400063300001600107650002900123650001300152  a0749247835  a516.9bOPE  aUnit 2 b inversive geometry  aKeynesbThe open universityc1994g1994  a68p.c30cm.  aNON-EUCLIDEAN GEOMETRIES  aGEOMETRY