Me solving those seven equation 12x-9=8x-37 , 11x=8x-6, -x-29=13+2x ,2(4x+7)=2x-4 ,2x+15=43-5x ,-14+3(x+10)=7(2x+4)+x , and 8(x+3=12x-4

18

step-by-step explanation:

draw the shape and you will see that f and k are actually at adjacent vertices (points of the hexagon that are neighboring).   so find the distance between (1,2) and (4,2).   that is easy since (1,2) and (4,2) is just a vertical distance to count, which is 3.   it is a regular polygon which means all sides are congruent.   you have 6 sides (hexa) so multiply 6 by 3 to receive 18.