Answer:
x°=21°
Explanation:
the angle where b is, is 54°, and this angle is equal to the angle that's left of 105°. The degree of line DE is 180°. Subtract 105° and 54° from 180° to get the missing angle that's on the right side of 105°. That angle would be 21°, and this angle is directly across the missing x°. So, x°=21°.
180-105-54=21 ----> this angle is directly across from the missing x°.