How to combine two trendlines from two different plot?

I have array data. Let's say time, x, and y. They are all 117*1 array. Then i make plots. And then i add a trendline for each plot using polyfit.

aa=polyfit(time,x,1);
bb=polyval(aa,time);
figure
plot(time,x)
hold on 
plot(time,bb)

cc=polyfit(time,y,1);
dd=polyval(cc,time);
figure
plot(time,y)
hold on
plot(time,dd)

So then i have 2 figures with 2 trendlines. I have a trouble about how to combine these two trendline in one figure. So that i can calculate the angle between the trendlines. Thank you..

Answer 1

[Birdman]

One figure definition is enough.

aa=polyfit(time,x,1);
bb=polyval(aa,time);
figure
plot(time,x)
hold on 
plot(time,bb)
cc=polyfit(time,y,1);
dd=polyval(cc,time);
plot(time,y)
plot(time,dd)