Check to see if a list of coords form a square

isSquare.js

var isSquare = function(cords){
	console.log(cords);
	for(var i=0;i<cords.length-1;i++){
		var currentVector = Math.pow(cords[i].x-cords[i+1].x,2) + Math.pow(cords[i].y-cords[i+1].y,2);
		if(i==0){
			previousVector = currentVector;
			console.log(currentVector, previousVector);
		}
		else{
			console.log(currentVector, previousVector);
			if( currentVector*2 == previousVector || currentVector/2 == previousVector  || currentVector==previousVector){
				
			}	else{
				return false;
			}

		}
	}
	return true;
}

var cords = [ 
 	{ x:8, y:3 },
 	{ x:7, y:8 },
 	{ x:2, y:7 },
 	{ x:3, y:2}
];
console.log('Is Funtion: '+isSquare(cords));