If you really want to know about angels, I suggest you consult with your local clergyman or tribal shaman representing the religion/sect/denomination of your choice. On the other hand if you want to know about angles, you should say so.
Supplementary angles are two angles such that the sum of their measures is 180 degrees. So if one of your angles is and the other is 18 degrees less than twice the other, which is to say , then:
Solve for , then calculate
John
Egw to Beta kai to Sigma
My calculator said it, I believe it, that settles it