Since the two lines are parallel and one line (called a transversal) goes through them both, angle x and the given angle are corresponding angles. That makes them equal to each other.
For this case we have the following equation: V = I * R Where, V: voltage I: current R: resistance By clearing R we have: R = V / I Substituting the values: R = (20) / (0.57) R = 35.09 Ohms Answer: The resistance of the light bulb is: R = 35.09 Ohms