Answer:
Undefined, it can be 20 cm, 22 cm or any value.A triangle has no limitations for any of each three sides.
Explanation:
How it works? The triangles have no limits on their sides, but by their angles. Each triangle sums 180 degrees at the inner angles. If you don't have specific values for the angles it is not necessary to get some values for the third side. It could be 1, 2, .... or even 1000.