Solution (1) :
∠y and ∠x are alternate interior angles . Both of these angles will be equal in measure when on two parallel lines with a transversal .
Solution (2) :
∠y and ∠x are alternate interior angles . Both of these angles will have an equal angle measure when they lie on two parallel lines with a transversal .
Solution (3) :
∠y and ∠x vertically opposite angles . Both of these angles will be equal in measure when on two parallel lines with a transversal .
Solution (4) :
∠y and ∠x are adjacent angles as well as a linear pair . These angles will sum up to form 180° .
