You can
put this solution on YOUR website!
Draw two isosceles triangles and label them:
Leg 1 + Leg 2 + Base = Perimeter
2a + 2a + b = 4a + b
b/2 + b/2 + 4a = 4a + b
In the first case 4a must be greater than b, by the
triangle inequality.
In the second case, b must be greater than 4a. by the
triangle inequality
Do not give this as an answer:
a + a + 2a + b = 4a + b
because it does not satisfy the triangle inequality.
Edwin