If three times the supp. of an angle is subtracted from seven times the comp. of the angle, the answer is the same a that obtained by trisecting a right angle. find the supplement.

Alright, let's start by giving some notation to "an angle." We'll use the Greek letter  to denote it.

Next, we'll need to review a few definitions:

- Two supplementary angles add up to a straight angle, or 180°
- Two complementary angles add up to a right angle, or 90°
- Trisecting an angle is splitting a larger angle into three equal smaller angles.

If we call 's supplement  and 's complement , we know that:



or, if we want to put everything in terms of :



We're given from the problem that  is being subtracted from , which in terms of  gives us:



Next, we're told that this expression is equal to the angle obtained by trisecting a right angle. A right angle is equal to 90°, so trisecting it, we get the angle 90°/3 = 30°.

Putting everything together, we have:



From there, solve for , but remember that the question asks for the supplement of , not  itself. Fortunately, we have an equation from earlier for the supplement, :



Simply put your result from solving for  into that equation and solve, and you'll have your answer.