#ex_02-1
#Learning Perl Appendix A, Exercise 2.1
$pi = 3.141592654;
$result = 2 * $pi * 12.5;
print "radius 12.5 is circumference $result\n";


#ex_02-2
#Learning Perl Appendix A, Exercise 2.2
print "What is the radius: ";
chomp($radius = <STDIN>);
$pi = 3.141592654;
$result = 2 * $pi * $radius;
print "radius $radius is circumference $result\n";



#ex_02-3
#Learning Perl Appendix A, Exercise 2.3
print "First number: "; 
chomp($a = <STDIN>);
print "Second number: "; 
chomp($b = <STDIN>);
$c = $a * $b; print "Answer is $c.\n";


#ex_02-4
#Learning Perl Appendix A, Exercise 2.4
print "String: "; $a = <STDIN>;
print "Number of times: "; chomp($b = <STDIN>);
$c = $a x $b; print "The result is:\n$c";