Question 349645
BY DEFINITION THE SUM OF COMPLEMENTARY ANGLES IS 90 DEGREES!
{{{C[1]+C[2]=90}}} 
PROBLEM STATES! {{{C[2]}}} IS {{{(C[1]+20)}}}
SUBSITUTE
{{{C[1]+(C[1]+20) =90}}}
COMBINE
{{{2C[1]+20 =90}}}
SOLVE:
{{{2C[1] = 70}}}

{{{C[1]= 35}}}
FIND C[2] = (*C[1]+ 20)!!!
{{{C[2]=55}}}
. 
CHECK YOUR ANSWERS!! 35 + 55  = 90