How to fill the area between two curves?

I want to shade the portion between red curve and green curve, but im not getting the proper way of doing it. Can anyone help me with your idea? I have attached a code and the figure for your reference.
Lx = 150;
Ly = 150;
T0 =0;
T1 = pi/4;
T=3.175;
N=8;
W=N*T;
X0=Lx/2;
Y0=0;
W_nominal=W/2;
for a=1:2
r=rem(a,2);
if r==0
xp=0; xn=0; i=1;
while (xp>=0 && xp<=Lx/2)
XPaxisl(i)=xp+(i-1)*Lx/1200; xp=XPaxisl(i);
XNaxisl(i)=xn+(i-1)*(-Lx)/1200; xn=XNaxisl(i);
Th(i)=T0+2*((T1-T0)*(XPaxisl(i)))/Lx;
TH(i)= T0+2*((T0-T1)*(XNaxisl(i)))/Lx;
Wp(i)=W_nominal/cos(Th(i));
WP(i)=W_nominal/cos(TH(i));
ypl(i)=Wp(i)+(Lx/(2*(T0-T1))*((-log(cos(T0)))+log(cos(T0+((2*(T1-T0)*XPaxisl(i))/Lx)))));
ynl(i)=WP(i)+(Lx/(2*(T1-T0))*((-log(cos(T0)))+log(cos(T0+((2*(T0-T1)*XNaxisl(i))/Lx)))));
i=i+1;
end
%figure(1)
plot(XPaxisl,ypl, '-g')
hold on
plot(XNaxisl,ynl, '-g')
hold on
x1 = XPaxisl;
y1 = ypl;
x2 = XNaxisl;
y2 = ynl;
end
%% shifting
r=rem(a,2);
if r==0
xp=0; xn=0; i=1; y=0; yn=0;
while (xp>=0 && xp<=Lx/2) && (y<=Ly/2)
XPaxiss1(i)=xp+(i-1)*Lx/1200; xp=XPaxiss1(i);
yps1(i) =(a*W_nominal)+Lx/(2*(T0-T1))*((-log(cos(T0)))+log(cos(T0+((2*(T1-T0)*XPaxiss1(i))/Lx))));
i=i+1;
end
else
xp=0; xn=0; i=1; y=0; yn=0;
while (xp>=0 && xp<=Lx/2) && (y<=Ly/2)
XPaxiss1(i)=xp+(i-1)*Lx/1200; xp=XPaxiss1(i);
XNaxiss1(i)=xn+(i-1)*(-Lx)/1200; xn=XNaxiss1(i);
yps1(i) =(a*W_nominal)+Lx/(2*(T0-T1))*((-log(cos(T0)))+log(cos(T0+((2*(T1-T0)*XPaxiss1(i))/Lx))));
yns1(i)= (a*W_nominal)+Lx/(2*(T1-T0))*((-log(cos(T0)))+log(cos(T0+((2*(T0-T1)*XNaxiss1(i))/Lx))));
i=i+1;
end
plot(XPaxiss1,yps1, '-r')
hold on
plot(XNaxiss1,yns1, '-r')
xlim([-Lx/2 Lx/2])
ylim([-Ly/2 Ly/2])
x3 = XPaxiss1;
y3 = yps1;
x4 = XNaxiss1;
y4 = yns1;
end
end
x2=x2(end:-1:1);
y2=y2(end:-1:1);
x4=x4(end:-1:1);
y4=y4(end:-1:1);
X1 = horzcat(x2(1:end-1),x1)
Y1 = horzcat(y2(1:end-1),y1);
X2 = horzcat(x4(1:end-1),x3)
Y2 = horzcat(y4(1:end-1),y3);
%figure(2)
%plot(X1,Y1)
%hold on
%plot(X2,Y2)
%xlim([-Lx/2 Lx/2])
%ylim([-Ly/2 Ly/2])
Area = trapz(X1,abs(Y1-Y2))

Answer 1

[KSSV]

clear all %clear all variables
clc % clear output screen
Lx = 150;     
Ly = 150;     
T0 =0;      
T1 = pi/4;   
T=3.175;
N=8;
W=N*T;
X0=Lx/2;
Y0=0;
W_nominal=W/2;
for a=1:2
    r=rem(a,2);
    if r==0
        xp=0; xn=0; i=1;
        while (xp>=0 && xp<=Lx/2) 
            XPaxisl(i)=xp+(i-1)*Lx/1200;     xp=XPaxisl(i);
            XNaxisl(i)=xn+(i-1)*(-Lx)/1200;  xn=XNaxisl(i);
            Th(i)=T0+2*((T1-T0)*(XPaxisl(i)))/Lx;
            TH(i)= T0+2*((T0-T1)*(XNaxisl(i)))/Lx;
            Wp(i)=W_nominal/cos(Th(i));
            WP(i)=W_nominal/cos(TH(i));
            ypl(i)=Wp(i)+(Lx/(2*(T0-T1))*((-log(cos(T0)))+log(cos(T0+((2*(T1-T0)*XPaxisl(i))/Lx)))));
            ynl(i)=WP(i)+(Lx/(2*(T1-T0))*((-log(cos(T0)))+log(cos(T0+((2*(T0-T1)*XNaxisl(i))/Lx)))));
            i=i+1;
        end
        %figure(1)
        plot(XPaxisl,ypl, '-g')
        hold on
        plot(XNaxisl,ynl, '-g')
        hold on
        x1 = XPaxisl;
        y1 = ypl;
        x2 = XNaxisl;
        y2 = ynl;
    end
    %% shifting 
    r=rem(a,2);
    if r==0
        xp=0; xn=0; i=1; y=0; yn=0;
        while (xp>=0 && xp<=Lx/2) && (y<=Ly/2)
            XPaxiss1(i)=xp+(i-1)*Lx/1200;     xp=XPaxiss1(i);
            yps1(i) =(a*W_nominal)+Lx/(2*(T0-T1))*((-log(cos(T0)))+log(cos(T0+((2*(T1-T0)*XPaxiss1(i))/Lx))));
            i=i+1;
        end
    else
        xp=0; xn=0; i=1; y=0; yn=0;
        while (xp>=0 && xp<=Lx/2) && (y<=Ly/2)
            XPaxiss1(i)=xp+(i-1)*Lx/1200;     xp=XPaxiss1(i);
            XNaxiss1(i)=xn+(i-1)*(-Lx)/1200;  xn=XNaxiss1(i);
            yps1(i) =(a*W_nominal)+Lx/(2*(T0-T1))*((-log(cos(T0)))+log(cos(T0+((2*(T1-T0)*XPaxiss1(i))/Lx))));
            yns1(i)= (a*W_nominal)+Lx/(2*(T1-T0))*((-log(cos(T0)))+log(cos(T0+((2*(T0-T1)*XNaxiss1(i))/Lx))));
            i=i+1;
        end
        plot(XPaxiss1,yps1, '-r')
        hold on
        plot(XNaxiss1,yns1, '-r') 
        xlim([-Lx/2 Lx/2])
        ylim([-Ly/2 Ly/2])
        x3 = XPaxiss1;
        y3 = yps1;
        x4 = XNaxiss1;
        y4 = yns1;
    end
end
x2=x2(end:-1:1);
y2=y2(end:-1:1);
x4=x4(end:-1:1);
y4=y4(end:-1:1);
X1 = horzcat(x2(1:end-1),x1)

X1 = 1×71

-78.7500 -74.3750 -70.1250 -66.0000 -62.0000 -58.1250 -54.3750 -50.7500 -47.2500 -43.8750 -40.6250 -37.5000 -34.5000 -31.6250 -28.8750 -26.2500 -23.7500 -21.3750 -19.1250 -17.0000 -15.0000 -13.1250 -11.3750 -9.7500 -8.2500 -6.8750 -5.6250 -4.5000 -3.5000 -2.6250

Y1 = horzcat(y2(1:end-1),y1);
X2 = horzcat(x4(1:end-1),x3)

X2 = 1×71

-78.7500 -74.3750 -70.1250 -66.0000 -62.0000 -58.1250 -54.3750 -50.7500 -47.2500 -43.8750 -40.6250 -37.5000 -34.5000 -31.6250 -28.8750 -26.2500 -23.7500 -21.3750 -19.1250 -17.0000 -15.0000 -13.1250 -11.3750 -9.7500 -8.2500 -6.8750 -5.6250 -4.5000 -3.5000 -2.6250

Y2 = horzcat(y4(1:end-1),y3);
%figure(2)
%plot(X1,Y1)
%hold on
%plot(X2,Y2)
%xlim([-Lx/2 Lx/2])
%ylim([-Ly/2 Ly/2])
Area = trapz(X1,abs(Y1-Y2)) ;
% DRaw color across the area
X = [X1 flip(X1)] ;
Y = [Y1 flip(Y2)] ;
patch(X,Y,'r')

Answer 2

[Sulaymon Eshkabilov]

Here are a couple of good examples how to achieve this task:

https://www.mathworks.com/matlabcentral/answers/180829-shade-area-between-graphs#:~:text=This%20can%20be%20simplified%20using%20the%20function%20shade,is%20above%202%20or%20the%20other%20way%20round.