Given the differential equation

The solution is as follows:
The 6 angles with vertex P are:
- Angle APB
- Angle APC
- Angle APD
- Angle BPC
- Angle BPD
- Angle CPD
The letter P must be in the middle since this location is the vertex. Something like angle BPA is the same as angle APB. We can swap the order of the outer letters without any change to the angle itself. Effectively, this means each angle has two possible names.
I drive 25 miles per day
divide the number of miles per day by the total miles to find how long it will take:
10,000 miles / 25 miles per day = 400 days