Decades: 1220s 1230s 1240s 1250s 1260s - 1270s - 1280s 1290s 1300s 1310s 1320s
Years: 1267 1268 1269 1270 1271 - 1272 - 1273 1274 1275 1276 1277
Births
Deaths
... square[?]. To "complete the square" is to add a constant (i.e., in this case, a quantity that does not depend on x) to the expression to the left of "=", that will make it ...