In the following diagram, BC is parrel to DE.
What is the measure of

x°=21°

Step-by-step 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°.

if you was gonna solve for a, a is a   < -12

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