Question 1131597


the sum of the two angles equals {{{180}}}° : 

{{{alpha+beta=180}}}°

if angle {{{alpha}}} is {{{30}}} degrees {{{more}}} than {{{twice}}} the angle {{{beta}}}, we have

{{{alpha=2beta+30}}}°...substitute in  {{{alpha+beta=180}}}°

{{{2beta+30+beta=180}}}°

{{{3beta=180-30}}}°

{{{3beta=150}}}°

{{{beta=150/3}}}°

{{{beta=50}}}°

and

{{{alpha=2*50+30}}}°

{{{alpha=130}}}°