The military field has rectangle shape with the dimension of 16 km to 12 km and recently there are some drone activities around the area and drones are not welcome to the military region!
Your commander gives you an order to put some small 2-km range radar towers in the region to detect and track these drones while they are flying in the field then it will be eliminated! So you cannot have any blind spot in the region, that means radars need to cover whole region to track the drone all the time.
What is the minimum number of radar towers you need to guarantee there is no blind spot in the region?
- Radar tower has 2-km radius capacity, you may assume they are point for simplicity.
- Drones can be detected in spite of their height if they are in the horizontal range of the radar towers. In other words, this is 2-D question.
- Radars needed to be inside the military area for security.