Respuesta :

Answer:  x = 8

=================================================

Explanation

Rule: The three interior angles of any triangle always add to 180

Using that rule, we can say the following

(angle1)+(angle2)+(angle3) = 180

(6x-9)+(65)+(76) = 180

6x+(-9+65+76) = 180

6x + 132 = 180

6x = 180-132

6x = 48

x = 48/6

x = 8

This x value leads to 6x-9 = 6*8-9 = 48-9 = 39

The three interior angles of the triangle are: 39, 65, 76

They add to 39+65+76 = 180, which confirms our answer.