Answer 1

In ∆FAN,
∠F + ∠A + ∠N = 180^∘   (Angle sum property)
⇒ 80^∘ + 40^∘ + ∠N = 180^∘   
⇒ 120^∘ + ∠N = 180^∘
⇒ ∠N = 180^∘ − 120^∘
= 60^∘
Now, in △FAN,  ∠F and ∠A are the largest and smallest angle.
The side opposite to the largest angle is the greatest side and the side opposite to the smallest angle is the smallest side .
Hence, the greatest and the smallest side of the triangle are AN and ​FN respectively.