Idon't know how to solve this. can someone me?

When the 2 sides of a triangle are equal ( in the figure shown both sides are 21) then the two bottom inside angles would aldo be equal to each other.

The three inside angles of a triangle need to equal 180 degrees.

Subtract the top angle from 180 and then divide by two:

180 - 38 = 142

X = 142 /2

X = 71 degrees.

its 50 miles away from the starting point