Find the value of n°.

Solution:

The angle marked with a square is a right angle, which measures 90°. The angle n° and the adjacent angle of 18° form this right angle. Therefore, their sum is 90°.

\( n° + 18° = 90° \)

\( n° = 90° - 18° \)

\( n° = 72° \)

Answer: 72