I'm not use of the formula, I am supposed to use

Answer:
39
Step-by-step explanation:
This is a right triangle so we can use trig functions
cos theta = adj side/ hypotenuse
cos ? = 41/53
Take the inverse cos of each side
cos ^-1 cos (?) = cos ^-1 (41/53)
? = 39.3
To the nearest degree
? = 39