Answer:
223 degrees
Explanation:
We have the following information:
Magnitude of the resultant vector = 8 units
The resultant vector makes a counterclockwise angle with the positive x-axis

Our goal is to determine the magnitude and angle of the equilibriant vector.
We understand that the equilibrium vector has the same magnitude but is oriented in the opposite direction of the given vector.
Thus, the equilibrium vector's magnitude = 8 units
x-component of a vector=
Where v = Magnitude of vector
Using the formula:
x-component of the resultant vector=
y-component of the resultant vector=
x-component of the equilibrium vector=
y-component of the equilibrium vector=
Because the equilibrium vector lies in the third quadrant

The angle
is in the third quadrant
In the third quadrant, the angle =
The angle of the equilibrium vector measured from the positive x-axis in a counterclockwise direction is 180+43=223 degrees