What I found when field measuring was that it was much more attainable to get hypotenuses and heights, so that left me looking for arcsin. I had hoped to get this processed as an AoA, but I'm not quite there yet....

$ perl slope8.pl
bath-left
theta is 5.82263230478133
bath-middle
theta is 4.91710033552881
bath-right
theta is 4.84767847916148
dining-south
theta is 15.2575232904564
john-north
theta is 16.0133944239485
middle-front
theta is 24.6243183521641
south-front
theta is 14.4775121859299
$ cat slope8.pl
#!/usr/bin/perl -w
use strict;
use 5.010;
use Math::Trig;
BEGIN { push @INC, ".."; }
use utils1;

my @AoA;
my $aoa_ref = \@AoA;

my $tja = 0.4375/4.3125;
say "bath-left";
my $hja = asin $tja;
my $degrees  = rad2deg($hja);
say "theta is $degrees";

$tja = 0.375/4.375;
$hja = asin $tja;
say "bath-middle";
$degrees  = rad2deg($hja);
say "theta is $degrees";

say "bath-right";
$tja = 0.375/4.4375;
$hja = asin $tja;
$degrees  = rad2deg($hja);
say "theta is $degrees";

say "dining-south";
$tja = 1.25/4.75;
$hja = asin $tja;
$degrees  = rad2deg($hja);
say "theta is $degrees";

say "john-north";
$tja = 1.0/3.625;
$hja = asin $tja;
$degrees  = rad2deg($hja);
say "theta is $degrees";

say "middle-front";
$tja = 1.875/4.5;
$hja = asin $tja;
$degrees  = rad2deg($hja);
say "theta is $degrees";

say "south-front";
$tja = 1.125/4.5;
$hja = asin $tja;
$degrees  = rad2deg($hja);
say "theta is $degrees";
__END__ 
$
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