Question 1147863
<pre> 
Since angle measures are often denoted by Greek letters, I will assume
that you mean the angle between the two lines indicated by the capital letter pairs. 
<font face="symbol">a</font> between FB and FE
{{{drawing(400,250,-6,5,-1,8,
line(-5,0,0,0), line(4,4,0,0), line(4,4,4,7), line(-1,7,4,7,0), line(-1,7,-5,3), line(-5,3,0,3), line(0,3,4,7), line(0,0,0,3), line(-5,0,-5,3),  
red(line(0,0,4,7),arc(0,0,3,-3,45,62)), locate(1,1.84,alpha),
locate(4.05,5.6,8),locate(2.4,2.5,16),
 
locate(0,0,F),locate(4,7.5,B), locate(4,4,E) )}}}{{{matrix(11,1,"","","","",
tan(alpha)="BE"/"FE",
tan(alpha)=8/16,
tan(alpha)=0.5,
alpha = 36.56505118^o,"","","" )}}}
<font face="symbol">b</font> between GC and GD
{{{drawing(400,250,-6,5,-1,8,
line(-5,0,0,0), line(4,4,0,0), line(4,4,4,7), line(-1,7,4,7,0), line(-1,7,-5,3), line(-5,3,0,3), line(0,3,4,7), line(0,0,0,3), line(-5,0,-5,3),  
red(line(-5,0,0,3),arc(-5,0,3,-3,31,90)), locate(-4.75,1,beta),
locate(4.05,5.6,8),locate(2.4,2.5,16),
locate(-2.7,0,13), locate(-2.7,3.6,13),locate(-5.35,3.1,D), locate(-5.35,1.7,8),
 
locate(.1,3,C), locate(-5,0,G) )}}}{{{matrix(11,1,"","","","",
tan(beta)="CD"/"DG",
tan(beta)=13/8,
tan(beta)=1.625,
beta = 58.39249775^o,"","","" )}}}
<font face="symbol">q</font> between CA and CH
<pre>
[Note: Angle CAH is a right (90°) angle though the perspective drawing below
might fool you]

{{{drawing(400,250,-6,5,-1,8,
line(-5,0,0,0), line(4,4,0,0), line(4,4,4,7), line(-1,7,4,7,0), line(-1,7,-5,3), line(-5,3,0,3), line(0,3,4,7), line(0,0,0,3), line(-5,0,-5,3),  
red(line(0,3,-1,7),arc(0,3,2,-2,103,138), line(0,3,-1,4)), locate(-.4,3.8,theta), 
locate(-1.34,7.5,A),
locate(-1.34,4.3,H),
locate(4.05,5.6,8),locate(2.4,2.5,16),locate(.1,3,C),
green(line(-1,4,-1,7), line(-1,4,-5,0),line(-1,4,4,4) ),
locate(1,7.55,13), 
locate(-5.35,3.1,D),
locate(0,0,F),locate(4,7.5,B), locate(4,4,E) )}}}{{{matrix(10,1,"","",
AC^2=AB^2+BC^2,
AC^2=13^2+16^2,
AC^2=169+256,
AC^2=425,

AC=sqrt(425),
AC=20.61552813,"","" )}}}{{{matrix(11,1,"","","","",
tan(theta)="AH"/"AC",
tan(theta)=8/20.61552813,
tan(theta)=0.388057,
theta = 21.20909151^o,"","","" )}}}
</pre>
<font face="symbol">g</font> between BE and ED
<pre>
[Note that the two diagonals of rectangle ABCD are equal, so BD=AC=20.61552813]
{{{drawing(400,250,-6,5,-1,8,
line(-5,0,0,0), line(4,4,0,0), line(4,4,4,7), line(-1,7,4,7,0), line(-1,7,-5,3), line(-5,3,0,3), line(0,3,4,7), line(0,0,0,3), line(-5,0,-5,3),  
red(line(4,4,-5,3),arc(4,4,2,-2,90,183)), 
locate(-1.34,7.5,A),    locate(3.3,4.8,gamma),
locate(-1.34,4.3,H),

blue(line(-5,3,4,7)),

locate(4.05,5.6,8),locate(2.4,2.5,16),locate(.1,3,C),
green(line(-1,4,-1,7), line(-1,4,-5,0),line(-1,4,4,4) ),
locate(1,7.55,13), 
locate(-5.35,3.1,D),
locate(0,0,F),locate(4,7.5,B), locate(4,4,E) )}}}{{{matrix(11,1,"","","","",
tan(gamma)="BD"/"BE",
tan(gamma)=20.61552813/8,
tan(gamma)=2.576941016,
gamma = 68.79090839^o,"","","" )}}}
</pre>
<font face="symbol">j</font> between FA and FC
<pre>
This angle is equal to one of the above angles calculated above.  Can
you tell which one it is?

Edwin</pre>