Answer:
<em>11) </em><em>80°</em>
<em>12) </em><em>80°</em>
<em>13) </em><em>80°</em>
<em>14) </em><em>40°</em>
<em>15) </em><em>60°</em>
<em>16) </em><em>120°</em>
<em>17) </em><em>180°</em>
<em>18) </em><em>100°</em>
<em>19) </em><em>120°</em>
<em>20) </em><em>280°</em>
Step-by-step explanation:
This will take awhile, so I will just give you the theorems I used to determine my answer.
11) Supplementary angles theorem
12) Central Angles/Arcs Theorem
13) Vertical Angles Theorem
14) Central Angles/Arcs Theorem
15) Vertical Angles Theorem (The vertical angle minus 40 would equal 60)
16) Supplementary Angles Theorem (Supplementary to 100 degrees)
17) Central Angles/Arc Theorem
18) Vertical Angles & Central Angles/Arc Theorem
19) Angle Addition Postulate, somewhat
20) Angle Addition Postulate
<em>Have a nice day, fam. This problem really worked my brain. Spread The Love.</em>