@lumino_iq_math Three lines: a regular triangle (60 degree angle)
Four lines: a square (90 degree angle)
Five lines: a pentagon (108 degree angle)
Six lines will be a regular hexagon (120 degree angle)
@lumino_iq_math maybe declining squares? the sum of the digits in the first box gives 49; 36 in the second; 25 in the third... if it must be 16 in the fourth, then ? = 30