Note: Figure not drawn to scale.
In the above figure, m∠AOC = 21° and m∠BOD = (2x + 39)°.
If ∠AOC and ∠BOD are vertical angles, what is the value of x?
(2 points)
Responses
x = 30
x = 30
x = 60
x = 60
x = -18
x = -18
x = -9
If ∠AOC and ∠BOD are vertical angles, then they are congruent, meaning they have the same measure.
So, we can set up an equation:
21° = (2x + 39)°
Now, we can solve for x by subtracting 39° from both sides and then dividing by 2:
21° - 39° = (2x + 39)° - 39°
-18° = 2x°
Dividing by 2:
-9° = x
So, x = -9.
Therefore, the value of x is -9.