Respuesta :

choixongdong
An exterior angle of a triangle is equal to the sum of the opposite interior angles

so
n = (180 - 133) + (180 - 142)
n = 47 + 38
n = 85

answer is A. 85
133  = 38 + m angle adjacent to n  (exterior angle of triangle theorem)
so m this angle =  133 - 38 = 95 degrees
Thus m  n = 180 - 95  = 68 degress

Its option A.