Answer :

luana
[tex]Those\ two\ angles\ measure\ 180^{\circ}\\\\ x-\ angle\\\\ x+89=180\ \ \ \ | subtract\ 89\\\\ x=91^{\circ}\\\\ Other\ angle\ measures \ 91^{\circ}.[/tex]
 A "straight angle" is a straight line.
 The angle of a straight line is 180 degrees. 
 The value of 2 angles add together to make 180
 One of the angles = 89 degrees
 The value of the second angle = 180-89 = 91