In order to study geometry logically, it will be important to understand key mathematical properties and to know how to apply useful postulates and theorems. a postulate is a proposition that has not been proven true but is considered to be true on the basis for mathematical reasoning.
The answer is 57 because using remote angles theorem you get the largest angle equals to 66 degrees but you are not done yet you have to subtract 66 from 180 because of sum of angles in a triangle so you get 114 degrees and since you have an isosceles triangle you have to divide by two to get y so y = 57 degrees
Yes you would be able to determine the other measures of the triangle.
