$(window).ready(function(){
    $('#triangle-calculator').submit(function(e){
        e.preventDefault();
        //
        // Code start here
        //
        var triangleType = 'Not a triangle';

        var a = parseInt( $('#a_number').val() );
        var b = parseInt( $('#b_number').val() );
        var c = parseInt( $('#c_number').val() );

        if ( ( a < 0 || a > 200 ) && ( b < 0 || b > 200 ) && ( c < 0 || c > 200 ) ) {
            triangleType = 'Some input value is out of range';
        } else {

            if ( a <= b + c && b <= a + c && c <= a + b ) {

                if ( a == b && a == c ) {
                    triangleType = 'Equilateral';
                } else if ( a != b && b != c && c != a ) {
                    triangleType = 'Scalene';
                } else {
                    triangleType = 'Isoscalene';
                }

            }

        }

        $('#log-msg').append('Triangle type: ' + triangleType + "\n");
        // 
        // Code end here
        // 
    });
});

$(window).ready(function(){
    $('#triangle-calculator').submit(function(e){
        e.preventDefault();
        //
        // Code start here
        //
        var triangleType = 'Not a triangle';

        var a = parseInt( $('#a_number').val() );
        var b = parseInt( $('#b_number').val() );
        var c = parseInt( $('#c_number').val() );

        if ( ( a < 0 || a > 200 ) || ( b < 0 || b > 200 ) || ( c < 0 || c > 200 ) ) {
            triangleType = 'Some input value is out of range';
        } else {

            if ( a <= b + c && b <= a + c && c <= a + b ) {

                if ( a == b && a == c ) {
                    triangleType = 'Equilateral';
                } else if ( a != b && b != c && c != a ) {
                    triangleType = 'Scalene';
                } else {
                    triangleType = 'Isoscalene';
                }

            }

        }

        $('#log-msg').append('Triangle type: ' + triangleType + "\n");
        // 
        // Code end here
        // 
    });
});

Update triangle validate check at main script
Update triangle validate check at main script
