Eight figures are below. Which ones are convex polygons?

[asy]
size(0,8cm);
draw((0,0)--(8,0)--(8,4)--(0,4)--cycle,black+2);
draw((2,0)--(2,4),black+1);
draw((4,0)--(4,4),black+1);
draw((6,0)--(6,4),black+1);
draw((0,2)--(8,2),black+1);
label("A",(0,4),SE);
label("B",(2,4),SE);
label("C",(4,4),SE);
label("D",(6,4),SE);
label("E",(0,2),SE);
label("F",(2,2),SE);
label("G",(4,2),SE);
label("H",(6,2),SE);
draw(shift(1,3)*scale(0.75)*rotate(22.5)*polygon(8),red+2);
draw((1.75,3)--(1.75,2.25),red+2);
draw(shift(2.375,2.375)*scale(1.25)*((1,0)--(1,1)--(0,1)--(0,0)--(1/12,1/2)--(2/12,0)--(3/12,1/2)--(4/12,0)--(5/12,1/2)--(6/12,0)--(7/12,1/2)--(8/12,0)--(9/12,1/2)--(10/12,0)--(11/12,1/2)--cycle),blue+2);
draw(shift(5,3)*scale(0.75)*polygon(13),red+2);
draw(shift(7,3)*scale(0.75)*(dir(0)--dir(60)--dir(120)--dir(180)--dir(210)--dir(240)--dir(270)--dir(300)--dir(330)--cycle),blue+2);
draw(arc((0.5,1),0.25,270,0)--arc((1,1),0.25,180,0)--arc((1.5,1),0.25,180,-90)--cycle,blue+2);
draw(shift(2.25,0.25)*scale(1.5)*((0.5,0.5)+0.5*dir(180)--(0.5,0.5)+0.5*dir(160)--(0.5,0.5)+0.5*dir(120)--(0.5,0.5)+0.5*dir(90)--(1,0.85)--(0.85,0)--(0.3,0.1)--cycle),red+2);
draw(shift(5,1.375)*scale(0.375)*rotate(90)*polygon(6),blue+2);
draw(shift(5,0.625)*scale(0.375)*rotate(90)*polygon(6),blue+2);
draw(shift(7,1.125)*scale(0.75)*(dir(-90)--dir(-30)--dir(30)--(0,0)--dir(150)--dir(210)--cycle),red+2);
[/asy]