Well, I don’t know for sure but I would say
C- 53* east of south for 5 miles
It seems to be on a 45 degree angle but slightly off and it’s going south east in direct so that my best guess,
Sorry if I’m wrong in advance
subtract 1/3x
so that you can get qui equatio
4 * 10 = 40
5 * 10 = 50
6 * 10 = 60
The side length of the original large triangle are 40 feet, 50 feet, and 60 feet.