An isosceles triangle has legs with length 10 units. Which of the following could be the perimeter of the triangle? Choose all that apply. Explain your reasoning. A 22
B 20
C 32
D 39
E 40

By the Triangle Inequality Theorem, the range of possible lengths of the third side is 0 < x <
.
So, the perimeter for all possible triangles must be greater than
units and less than
units.