Step-by-step explanation
Since we have the triangle, and the measure m
We have two complementary angles inside the angle DBF,
m
Substituting terms:
x - 12 + x = 90
Adding like terms:
2x - 12 = 90
Adding +12 to both sides:
2x = 90 + 12
Adding numbers:
2x = 102
Dividing both sides by 2:
x = 102 / 2
Simplifying:
x = 51
Finally, by the Vertical Angles Theorem, we can affirm that the angles GBC and DBE are both congruent.
Plugging in x=51 into the given equation:
x-12
51-12=39
In conclusion, the measure of the angle GBC is of 39 degrees