Answer:
x = 6
Step-by-step explanation:
180° is always all triangles.
This is a right triangle, so that means that the angle that is unknown is 90.
Angles:
90
60
7x - 12
90 + 60 + 7x - 12 = 180
150 - 12 + 7x = 180
138 + 7x = 180
7x = 180 - 138
7x = 42
7x/7 = 42/7
x = 6
