Question 954390
in a parallelogram:

opposite sides are parallel
opposite sides are equal in length
opposite angles are equal 
the sum of all angles in a parallelogram is {{{360}}}


so,if one angle is {{{x}}} and its adjacent angle {{{2x}}}, then
 
{{{x + x + 2x + 2x = 360 }}}

{{{6x = 360 }}}

{{{x = 360/6 }}}

{{{highlight(x = 60 )}}}

and its adjacent angle {{{highlight(2x=120)}}}