Solver Find the area of triangle if 3 sides are given

Source code of 'Find the area of triangle if 3 sides are given'

This Solver (Find the area of triangle if 3 sides are given) was created by by hummingbird(0)

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==section input
Input the following side lengths of the triangle:

S1 = *[input s1=2],S2 = *[input s2=3]and S3 = *[input s3=4]

Find the Area of the Triangle

==section solution

perl
my $d1 = $s1 +$s2;
my $d2 = $s2 +$s3;
my $d3 = $s3 +$s1;

if($s1==0 || $s2==0 || $s3==0)
{
print " This is not a Triangle because atleast one of the side length is equal to zero. 
Please enter another set of values for S1,S2 and S3.";
}

elsif($d1==$s3 || $d2==$s1 || $d3==$s2)
{
print " This is not a Triangle because sum of two sides length is equal to the third side length.
Please enter another set of values for S1,S2 and S3.";
}

else 
{
  if(($s1+$s2<$s3) || ($s2+$s3<$s1) || ($s1+$s3<$s2) )
  {
print " These sides do not form a triangle. Please enter another set of values for S1,S2 and S3. 
";
  }

else
  {
  my $s = 1/2*($s1+$s2+$s3);
  my $a=sqrt($s*($s-$s1)*($s-$s2)*($s-$s3));

print "In any triangle, If the side lengths are known then the area of the triangle can be
calculated by the <A HREF=Heron%27s_formula.wikipedia>Heron's Formula</A>Heron's Formula.

{{{A = sqrt(S*(S-S1)*(S-S2)*(S-S3))}}}
Where {{{S = (S1+S2+S3)/2 }}} is the semi perimeter, or half of the triangle's perimeter.

equivalent Heron's Formula is:
{{{A= sqrt((s1+s2+s3)*(s1+s2-s3)*(s2+s3-s1)*(s1+s3-s2))/4}}}

In our case the desired value is:
{{{S = 1/2*($s1+$s2+$s3) = $s}}}
{{{A = sqrt($s*($s-$s1)*($s-$s2)*($s-$s3)) = $a}}}

So, the answer is that the Area of the Triangle with given parameter is $a .

For more on this topic, refer to <A HREF=Triangle.wikipedia>Triangle</A>
";
}
}
==section output
a,

==section check
  s1=4 s2=3 s3=5 a=3.464101615