Method for finding pythagorean triples in a given range. Returns the triple with the largest sum that is less than the given perimeter

triples.rb

def find_biggest_triple(perimeter)
  all_triples = [] # Empty array to hold all of the triplets
  max_side_length = perimeter/2 # This isn't necessary because we filter but the method runs a lot faster if we cut down how many times the all_triples loops need to run. a + b should always be greater than c so no need to build triples that won't be selected

  # Run outer loop perimeter/2 times - This is our hypotenuse
  max_side_length.times do |a|
    a.times do |b|
      b.times do |c|
        # Pythagorean triplet is found if the square of the two shorter sides (the two interior loops) equals the square of the hypotenuse
        if c**2 + b**2 == a**2
        # If sides are less than perimeter, add to triples array
          if c + b + a < perimeter
            all_triples << [a,b,c]
          end
        end
      end
    end
  end
  # The each method below breaks if biggest_triple isn't initalized to 0 here.
  biggest_triple = [0]

  all_triples.each do |nums|
    biggest_triple = nums if biggest_triple.inject(:+) < nums.inject(:+)
  end

  biggest_triple #=> Largest triplet in the given range
end

Good work! You could optimize it by calculating the last of the triplets (given a and b) and checking if the 3rd number would be an integer.