I need help fast like i apericiate the help i just dont get this

Answer:
30
Step-by-step explanation:
Since this is a right angle, we can use trig functions
Cos theta = adjacent side/ hypotenuse
cos ? = 20/23
Take the inverse cos of each side
cos ^-1 (cos ?) = cos ^-1(20/23)
? =29.59184579
To the nearest degree
? = 30