From the given figure
There is a right triangle
Its hypotenuse = 39
The side adjacent to the missing angle = 35
Since we have adjacent side, and hypotenuse, then we will use cos x
Use the inverse of cos to find x
Use the calculator to find x
x = 26.17695217
Round it to the whole number
x = 26 degrees
The measure of the missing angle is 26 degrees