Final answer:
Angle b measures 35°, as it is the complement of angle a which measures 55°, and together they must add up to 90°.
Step-by-step explanation:
You have stated that angle a and angle b are complementary angles, and if angle a measures 55°, we need to find the measure of angle b. Complementary angles are two angles whose measures add up to 90°. To find the measure of angle b, subtract the measure of angle a from 90°:
Measure of angle b = 90° - Measure of angle a
Measure of angle b = 90° - 55°
Measure of angle b = 35°.
Therefore, angle b measures 35°.