A rectangle has two pairs of opposite sides parallel, and four right angles. ... A square has two pairs of parallel sides, four right angles, and all four sides are equal. It is also a rectangle and a parallelogram.
Y= 10 because you have a 180 degree angle split in half which equals 90 degrees so 3•30=90 the the other side has to equal 90 degrees so 2•30=60 then 3•10=30 so then just add 60 and 20 and there is your 90