Answer:
complementary
x = 15
Explanation:
The outer angle is a right angle as denoted by the red square mark. A right angle has a measure of 90°.
Complementary angles are angles whose measures have a sum of 90°.
Angles 3x and 45 are complementary angles.
3x + 45 = 90
3x = 45
x = 15
Answer:
complementary
x = 15