World War I and II. These wars caused lots of economic growth and development because there was a pressure to create better inventions. Having better technology could mean the win or lose of a war. :D
Answer:
105°
Explanation:
Two angles are linear if their angle measures add up to 180°. (This is also known as vertical angles.)
If we know the measure of one angle, we can easily find the measure of the other, assuming x is the missing angle:

Hope this helped!