Based on the image, we have two parallel lines ( a ) and ( b ), intersected by two other parallel lines ( c ) and ( d ). We are given that one of the angles is ( 105^{\circ} ) and we need to find the value of the angle ( x ).
When parallel lines are intersected by another line, corresponding angles are equal. Also, supplementary angles add up to ( 180^{\circ} ).
Since line ( c ) intersects parallel lines ( a ) and ( b ), the angle corresponding to the ( 105^{\circ} ) angle is also ( 105^{\circ} ) on line ( a ).
Now, line ( d ) intersects parallel lines ( a ) and ( b ). The angle ( x ) and the ( 105^{\circ} ) angle are supplementary angles because they lie on the same side of the transversal line ( d ) and between the parallel lines ( a ) and ( b ). Therefore, their sum is ( 180^{\circ} ).
So, we can write the equation:
$$x + 105^{\circ} = 180^{\circ}$$
Solving for ( x ):
$$x = 180^{\circ} - 105^{\circ}$$
$$x = 75^{\circ}$$
Answer: 75