Question 178946
Your angle is {{{70degrees}}}.

If  that angle is {{{x}}}, we have:
{{{x + (90-x) +(180-x)=200}}}


{{{x + (90+180) +(-x-x)=200}}}

{{{x + 270 -2x =200}}}

{{{270 -x =200}}}

{{{270 -200 = x}}}


{{{  70 = x }}}

an angle that is complementary to angle {{{x }}}
{{{ 90 - 70 = 20}}}
an angle that is supplementary to angle {{{x }}}
{{{ 180 - 70 = 110}}}

Their sum:

{{{70 + 20 + 110=200}}}