Find the legs of isosceles triangle, given only the base Is it possible to find the legs of isosceles triangle, given only the base length? I think that the info is insufficient. Am I right?
The base length of an isosceles triangle is not enough to determine the triangle:

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You will always need three data to determine a triangle. It can be any combination of angles, lengths, heights...

In your example, since you know it's an isosceles triangle, you'll have three data once you define an angle or a length apart from the base's length, because you know both angles at the base's ends are equal.

So, if you have the segment AB being the base of an isosceles triangle, once you know either angle C, height from base to C, length BC or length AC, you'll have everything you need.