If B is obtuse, B > 90 degrees, then the remaining two angles add up to less than 90 degrees, so must be acute. In fact, at least one of A and C is less than 45 degrees, but we can't tell which.
It was really just testing it out, checking to see if an equation worked for one row, then try in the next. Its hard to explain, but its really just guess and check ;D
