Respuesta :

First take tan to the other side making it the inverse of tan. Then you put it in your calculator: Shift 2ndF tan 90 and you should get the following answer. 
X=tan^-1 (90) 
X=89.4 
mathnstuff
The inverse of tan(90) equals 89.3634 degrees.
To the nearest tenth, x = 89.4