Question 760836
The interior angles of a triangle add up to 180.
So {{{A + B + C = 180}}}
We are given C = 90. We can plug that into the equation.
{{{A + B + (90) = 180}}}
Subtract 90 from both sides.
{{{A + B = 90}}}
Let that be equation 1.
Equation 1: {{{A + B = 90}}}
Equation 2: {{{A = 2B}}}
Plug 2B into equation 1 for A
{{{2B + B = 90}}}
Combine like terms
{{{3B = 90}}}
Divide both sides by 3
{{{highlight(B = 30)}}}
Now plug 30 into equation 2 for B and solve for A.
Equation 2: {{{A = 2B}}}
{{{A = 2*(30)}}}
{{{highlight_green(A = 60)}}}