e. 72.
Let x be the measurement of the 3rd side.
x should be greater that the difference of 2 sides
x should be less than the sum of 2 sides
20 - 15 < x < 20 + 15
5 < x < 35
We can assume that x = 35 the maximum measurement of the 3rd side.
Perimeter = 20 + 15 + 35 = 70. Maximum perimeter.
Among the choices, 72 is beyond the maximum, so it is not a possible perimeter of the triangle.
