Answer:
The longest side is AD.
Step-by-step explanation:
The above question is based on a simple fact that, sides opposite to the largest angle is the largest side.
Above,
80+30+∠QDA = 180
∠QDA = 70 degrees and
82+46+∠QAU = 180
∠QAU = 57 degrees
In triangle QDA, 80 degrees is largest and so side DA is largest.
QD is opposite to 30 degrees, and so is smallest.
(while other 2 sides having 46 degrees and 57 degrees as opposite angles are intermediate sides)
