let
a---------> length of one of the two congruent sides of the triangle
we know that
The sum of the lengths of any two sides of a triangle is greater than the length of the third side (Triangle Inequality Theorem)
so
(a+a) > 8
2a > 8
a> 4
Rounded to the nearest tenth, the smallest possible length of a is 4.1
the answer is
4.1 units
