The larger the opening between two sides, the longer is its opposite side. Assuming ∠R is between RS and RT, its opposite is ST, ∠S is between RS and ST, its opposite is RT, ∠T is between ST and RT, its opposite is RS.
Thus, ∠T is the smallest angles because it has a corresponding smallest side.
When sides are doubled, the area of new triangle will always be 4 times the original, the change in area will be 3 times. Hence the % change will always be 300% irrespective of the type of triangle.
