Question 745773
As you said, two of the angles will measure {{{225-2x}}} degrees.
If each of the other two angles measures {{{x}}} degrees,
as we know that the measures of all four angles add up to {{{360^o}}},
{{{2(225-2x)+2x=360}}} --> {{{450-4x+2x=360}}} --> {{{450-2x=360}}} --> {{{-2x=360-450}}} --> {{{-2x=-90}}} --> {{{x=(-90)/(-2)}}} --> {{{highlight(x=45)}}}