Given:
Given that the measure of the exterior angle F is 142°
We need to determine the measure of ∠DFE
Measure of ∠DFE:
The ∠DFE and the exterior angle F are linear pairs.
Thus, the linear pair of angles add up to 180°
Hence, we have;
[tex]\angle DFE+142^{\circ}=180^{\circ}[/tex]
Subtracting both sides of the equation by 142, we get;
[tex]\angle DFE=38^{\circ}[/tex]
Hence, the measure of ∠DFE is 38°
Thus, Option a is the correct answer.
