You are 5'11''(180 cms) and 175lbs(79 kgs) .
For a man- ideal body weight should be ht in cms - 100 which in your case is 80kgs
you are ideal body weight and you should try to maintain this weight by eating healthy and following an active lifestyle. Stay physically active and stay away from vices like alcohol and smoking
.Eat small frequent meals and follow the principle of eat breakfast like a king, lunch like a prince and dinner like a beggar. Try and include nuts,vegetables,eggwhites and fruits in your diet.