How many squares are there in the square figure ABCD ?

The squares are : ABCD, AFUO, FBIU, OULD, UICL, EGVT, TVKM, PRXN, RHJX, QSYW, AEQP, PQTO, OTWN, NWMD, EFRQ, QRUT, TUXW, WXLM, FGSR, RSVU, UVYX, XYKL, GBHS, SHIV, VIJY, YJCK, AGYN, EBJW, PSKD, QHCM. Thus, there are 30 squares. Ilnd Method : Required number of squares $=\sum_{i=1}^4 n^2=1^2+2^2+3^2+4^2=30$