Just PHP FUN 105.

area_of_regular_polygon.php

<?php
# https://www.codewars.com/kata/565c9f5fcabeeaeb5a000052 Area of a regular polygon.
function area_of_regular_polygon(string $s): string {
  $not = 'Invalid input';
  echo "Input: $s\n";
  if( ! preg_match('/(\d+.?\d*) sides of (\d+.?\d*) (\w+) each/',$s,$match)) return $not;
  $n = (float) $match[1]; (float) $side = $match[2]; $units = $match[3];
  echo "$n - sides of $side length \n";
  if(2 >= $n || 0 >= $side || 0 != $n - floor($n)) return $not;
  $a = ($side*$side)*$n;
  $b = 4*tan(pi()/$n);
  
  return sprintf("%.2f sq.$units", round($a/$b,2));
  
}

just_php_fun_105.md

Just PHP FUN 105.

• https://www.codewars.com/kata/565c9f5fcabeeaeb5a000052 Area of a regular polygon.

Started at 21:10 2020.09.17 Thursday Sep.
Finished at 23:02 2020.09.17 Thursday Sep. (1hr 58minutes)