Find the side of an isosceles triangle if the other two sides are 8cm and 2cm.

The other side will also be 8 cm.
Explanation:
A triangle is isosceles if its two sides are equal. Accordingly, the unknown side will be either 8 cm or 2 cm. It cannot be 2 cm simply because if in a triangle two sides are equal to 2, and the third is 8, then those 2 cm sides simply will not converge into a triangle. We can say that they do not have enough length for this. You can take 8cm straws and two 2cm straws. Then try to connect them into a triangle without breaking them. Will not work)
Therefore, the two sides should be 8cm each, and the base should be 2cm.