We wanted to find a way for the invader to disable the radar undetected. Remember that Radar has a radius of 100 metres and rotates once every 12 seconds, and Invader runs at 7 m/s with their pack. Clearly, Invader waits until Radar has just passed it to begin. It takes Invader over 14 seconds to run straight to Radar. Maybe Invader could run a circle around Radar when it is about to catch up? For Invader yo circle Radar, they must be within 42/π, or 13.369, metres. That’s because the circle Invader runs must have radius 84 metres to be completed in 12 seconds. 7 m/s * 12 s = 84 m. This still leaves 86.631 metres left for Invader to run in 12 seconds, but they can only run 84 of them. So that’s a no. But what if Invader runs diagonally towards this circle? Invader then has 15 seconds to run √(1002+13.3692) = 100.89 metres. Invader can do 105! Invader does intersect the circle earlier on this path, so it’s not perfect, but it’s simple and works.