Angle difference between two bearings

sub infix:<∠> (Real $b1, Real $b2) {
   (my $b = ($b2 - $b1 + 720) % 360) > 180 ?? $b - 360 !! $b;
}

for 20, 45,
   -45, 45,
   -85, 90,
   -95, 90,
   -45, 125,
   -45, 145,
   29.4803, -88.6381,
   -78.3251, -159.036,
   -70099.74233810938, 29840.67437876723,
   -165313.6666297357, 33693.9894517456,
   1174.8380510598456, -154146.66490124757,
   60175.77306795546, 42213.07192354373

  -> $b1, $b2 { printf "%10.2f %10.2f = %8.2f\n", $b1, $b2, $b1 ∠ $b2 }

Output:

     20.00      45.00 =    25.00
    -45.00      45.00 =    90.00
    -85.00      90.00 =   175.00
    -95.00      90.00 =  -175.00
    -45.00     125.00 =   170.00
    -45.00     145.00 =  -170.00
     29.48     -88.64 =  -118.12
    -78.33    -159.04 =   -80.71
 -70099.74   29840.67 =  -139.58
-165313.67   33693.99 =   -72.34
   1174.84 -154146.66 =  -161.50
  60175.77   42213.07 =    37.30