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committed 6b69fda

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• Parent commits 89264f3

# File project-euler/91/Euler91.pm

`+package main;`
`+`
`+use strict;`
`+use warnings;`
`+`
`+=head1 DESCRIPTION`
`+`
`+The points P (x_(1), y_(1)) and Q (x_(2), y_(2)) are plotted at integer `
`+co-ordinates and are joined to the origin, O(0,0), to form ΔOPQ.`
`+`
`+There are exactly fourteen triangles containing a right angle that can be formed when each co-ordinate lies between 0 and 2 inclusive; that is,`
`+0 ≤ x_(1), y_(1), x_(2), y_(2) ≤ 2.`
`+`
`+Given that 0 ≤ x_(1), y_(1), x_(2), y_(2) ≤ 50, how many right triangles can`
`+be formed?`
`+`
`+=head1 ANALYSIS`
`+`
`+One can see that the right angle can be:`
`+`
`+=head2 In O.`
`+`
`+In this case, there are x_len * y_len triangles.`
`+`
`+=cut`
`+`
`+sub get_num_O_right_angle_triangles`
`+{`
`+    my (\$x_len, \$y_len) = @_;`
`+`
`+    return \$x_len * \$y_len;`
`+}`
`+`
`+1;`
`+`

# File project-euler/91/t/91.t

`+#!/usr/bin/perl`
`+`
`+use strict;`
`+use warnings;`
`+`
`+use Test::More tests => 1;`
`+`
`+use Euler91;`
`+`
`+# TEST`
`+is (get_num_O_right_angle_triangles(2,2), 4, "2*2 O triangles");`