ClearAll;
$DefaultFont = {"Times-Roman",10};
Needs["Graphics`Graphics`"];
f[t_] = Which[t<=1/20,0,
			  t<=1/10,465(20 t - 1),
			  t<=3/20,465,
			  t<=3/10,310(3 - 10t)];
F[t_] = Which[t<=1/20,0,
			  t<=1/10,93/8 - 465t + 4650t^2,
			  t<=3/20,465t - 279/8,
			  t<=3/10,930t - 1550t^2 - 279/4];

tri1[t_]:= Graphics[{GrayLevel[0.65],Polygon[{{0.05,0},{t,0},{t,465(20 t - 1)}}]}];
rect[t_]:= Graphics[{GrayLevel[0.35],Rectangle[{0.1,0},{t,465}]}];
tri2[t_]:= Graphics[{GrayLevel[0.65],Polygon[{{0.15,0},{0.15,465},{t,310(3 - 10t)},{t,0}}]}];
shade1 = Show[tri1[0.08],
			AxesLabel->{"x","y"},Axes->True,
			Ticks->{{{0.08,"t"}},Automatic},
			PlotLabel->"(a) Ventricular outflow (ml/s)\n\n        y = f(x)"];
shade2 = Show[tri1[0.1],rect[0.13],
			AxesLabel->{"x","y"},Axes->True,
			Ticks->{{{0.13,"t"}},Automatic},
			PlotLabel->"(b) Ventricular outflow (ml/s)\n\n        y = f(x)"];
shade3 = Show[tri1[0.1],rect[0.15],tri2[0.22],
			AxesLabel->{"x","y"},Axes->True,
			Ticks->{{{0.22,"t"}},Automatic},
			PlotLabel->"(c) Ventricular outflow (ml/s)\n\n        y = f(x)"];

plot1 = Show[shade1,Plot[f[t],{t,0,0.3}]];
plot2 = Show[shade2,Plot[f[t],{t,0,0.3}]];
plot3 = Show[shade3,Plot[f[t],{t,0,0.3}]];
plot4 = Show[Plot[F[t],{t,0,0.3}],AxesLabel->{"t","y"},Axes->True,
		PlotLabel->"(d) Blood discharged by time t (ml)\n\n        y = F(t)"];

Show[GraphicsArray[{{plot1,plot2},{plot3,plot4}}],
	PlotLabel->"Figure 9.2"]