Answer:
a.) 98°
Explanation:
Angle 5 and angle 8 (82°) are supplementary angles. This means that their sum will make a straight angle of 180°. Make an equation:

Solve for x, the value of angle 5:

Angle 5 has a measure of 98°.
Now we know the measure of angle 5. Angle 4 and angle 5 are alternate interior angles, so they are congruent. Therefore, angle 4 has a measure of 98°.
:Done