SOLUTION: in a triangle, the sum of all angles equals 180 degrees. If one angle equals 72 degrees, and then angle X is two times that of angle Y. I know the answer is X = 36 and Y = 72. My

Algebra ->  Triangles -> SOLUTION: in a triangle, the sum of all angles equals 180 degrees. If one angle equals 72 degrees, and then angle X is two times that of angle Y. I know the answer is X = 36 and Y = 72. My      Log On


   

Question 738135: in a triangle, the sum of all angles equals 180 degrees.
If one angle equals 72 degrees, and then angle X is two times that of angle Y. I know the answer is X = 36 and Y = 72. My question is, how do you get that answer?
Answer by fcabanski(1391) About Me  (Show Source):
You can put this solution on YOUR website!
Set up two equations.


1: Angle x is two times angle y: x=2y


2: The sum of all angles is 180 degrees: 72 + x + y = 180 so x+y = 180-72 = 108


Substitute 2y for x (as shown in equation 1) in equation 2. 2y+y = 108


3y = 108


y = 36


x = 2y = 2(36) = 72 degrees. You had it backwards...x is twice angle y.

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