a)

Input := 

Clear[level]
level[0]=ListPlot[{
	{0,0},{1,0}},
	PlotJoined->True,
	PlotStyle->{Red,Thickness[.01]},
	Ticks->{{{.25,"1/4"},{.5,"1/2"},{.75,"3/4"},{1,"1"}},
		{{.25,"1/4"},{-.25,"-1/4"}}},
	DisplayFunction->Identity
	]
level[1]=ListPlot[{
	{0,0},{.25,0},{.25,.25},{.5,.25},{.5,0},{.5,-.25},
		{.75,-.25},{.75,0},{1,0}},
	PlotJoined->True,
	PlotStyle->{Red,Thickness[.01]},
	Ticks->{{{.25,"1/4"},{.5,"1/2"},{.75,"3/4"},{1,"1"}},
		{{.25,"1/4"},{-.25,"-1/4"}}},
	AspectRatio->Automatic,
	DisplayFunction->Identity
	]
Show[GraphicsArray[{level[0],level[1]},
	DisplayFunction->$DisplayFunction]]

Output =

-Graphics-

Output =

-Graphics-

Output =

-GraphicsArray-

Answer:

N=8, r=1/4, so

Input := 

dimension[8,1/4]

Output =

1.5