The answer is 34.05
The total distance (D) is the sum of three distances (d1, d2, and d3).
The distance formula is

Distance 1: Phoenix (–12, –16) to Blythe (–20, –9)
:

Distance 2: Blythe (–20, –9) to Los Angeles (–33, –4):

Distance 3: Los Angeles (–33, –4) to San Francisco (–36, 5)

D = d1 + d2 + d3 = 10.63 + 13.93 + 9.49 = 34.05