Since MN forms a 180 degree angle, if you subtract 148.7 from 180, you get 31.3 degrees. This means angles L and N are both 31.3 degrees. Since the parallelogram is 360 degrees total, you subtract 62.6 to account for angles L and N. The remaining degrees unaccounted for are 297.4 degrees which you then divide by two to get the value of angles O and M, which would give you 148.7 degrees for each O and M. This means that angle x is 148.7 degrees
the value of root three is given already so the question is asking you to round it of to the nearest 1000 which means there should be three numbers after the decimal point.
