SOLUTION: the measure of one angle of a triangle is 1 degree less than twice the measure of the second angle, and the measure of the third angle is 21 degrees more than twice the sum of the

Algebra ->  Angles -> SOLUTION: the measure of one angle of a triangle is 1 degree less than twice the measure of the second angle, and the measure of the third angle is 21 degrees more than twice the sum of the       Log On


   



Question 159420: the measure of one angle of a triangle is 1 degree less than twice the measure of the second angle, and the measure of the third angle is 21 degrees more than twice the sum of the measures of the other two. find the measure of all three angles.
Found 2 solutions by vleith, jojo14344:
Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Let the smallest angle be s
You are told the second angle is 2s-1
You also told the third angle is 2%28s+%2B+%282s-1%29%29+%2B+21
All you need to do now is sum them all up and know that sum must be 180 (every triangle has 180 degrees in it)
180+=+s+%2B+%282s-1%29+%2B+%282%28s+%2B+%282s-1%29%29+%2B+21%29+
180+=+s+%2B+%282s-1%29+%2B+%282%283s-1%29%29+%2B+21%29+
180+=+s+%2B+%282s-1%29+%2B+%286s-61%29+%2B+21%29+
Now solve for s. Once you get s, plug that value back into the equations at the top of the solution to find angle 2 and angle 3
I think you can take it from here. let me know if you can't

Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!

Remember the following Angles=A:
A%5B1%5D=2A%5B2%5D-1, twice the 2nd Angle less 1 degree
A%5B2%5D=A%5B2%5D
A%5B3%5D=2%28A%5B1%5D%2BA%5B2%5D%29%2B21, twice the sum of Angle 1 & Angle 2 and more than 21
We a triangle measures 180 degrees. So,
A%5B1%5D%2BA%5B2%5D%2BA%5B3%5D=180,-----> working eqn
Substitute, distribute & combine similar terms below:
2A%5B2%5D-1%2BA%5B2%5D%2B2%28A%5B1%5D%2BA%5B2%5D%29%2B21=180
2A%5B2%5D-1%2BA%5B2%5D%2B2%282A%5B2%5D-1%2BA%5B2%5D%29%2B21=180
2A%5B2%5D-1%2BA%5B2%5D%2B4A%5B2%5D-2%2B2A%5B2%5D%2B21=180
9A%5B2%5D=180%2B1%2B2-21=162
cross%289%29A%5B2%5D%2Fcross%289%29=cross%28162%2918%2Fcross%289%29
A%5B2%5D=18degrees
A%5B1%5D=2%2A18-1=36-1=35degrees
A%5B3%5D=2%2835%2B18%29%2B21=2%2853%29%2B21=106%2B21=127degrees
check via working eqn:
35%2B18%2B127=180
180=180
Thank you,
Jojo