Question 906438


Two angles are supplementary. 

let's angles be {{{alpha}}} and {{{beta}}}

Supplementary angles  add up to {{{180}}}°.

so, {{{alpha+beta=180}}} ...eq.1


given: one angle is double the other:  let's say {{{alpha=2beta}}}...eq.2

go to {{{alpha+beta=180}}} ...eq.1 and substitute {{{alpha}}} from eq.2

{{{2beta+beta=180}}} ...solve for {{{beta}}}

{{{3beta=180}}}

{{{beta=180/3}}}

{{{beta=60}}} ...now go back to {{{alpha=2beta}}}...eq.2 and find {{{alpha}}}


{{{alpha=2*60}}}...eq.2

{{{alpha=120}}}

so, your angles are: {{{alpha=120}}}° and {{{beta=60}}}°