Final answer:
The speed to approach a right-hand turn depends on road conditions and traffic laws, and it is not specified in mph in the question. For the highway scenario provided, the ideal speed would be based on the highway's speed limit.
Step-by-step explanation:
When preparing to make a right-hand turn, the speed at which you approach the side of the road depends on various factors, such as road conditions and local traffic laws. However, the question seems to be asking about an ideal speed related to a different scenario regarding a highway turn at a gentle turn of 1.20 km radius. For this specific case, the ideal speed is the maximum safe speed a vehicle can maintain on a curve without relying on the friction between the tire and the road. Using the information provided, the ideal speed would be the one suitable for the scenario described such as a highway with a 105 km/h speed limit and a banking angle optimized for a 1.20 km radius turn.
Taking into account the additional context provided, if the question is in reference to the latter scenario, then we might infer that the correct approach speed for the right-hand turn should be calculated based on the road's curvature and legal speed limits, rather than a specified mph value. Remember to always check if the answer is reasonable and compare it with well-known units such as miles per hour for better understanding.