Question 1191970
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x = length of side AC
2x = length of side AB, since it's twice as long as AC


Triangle ABC is isosceles, meaning there are exactly two sides that are the same length.
We've already ruled out AB and AC being the same length.


It's not clear if BC = AC or if BC = AB


Both cases cannot be true simultaneously. Why not? Because that would lead to the false statement that AB = AC, when it should be AB > AC.


If BC = AC, then BC = x and,
AB+BC+AC = perimeter
2x+x+x = 200
4x = 200
x = 200/4
x = 50
So AC = 50


Or if BC = AB, then BC = 2x and,
AB+BC+AC = perimeter
2x+2x+x = 200
5x = 200
x = 200/5
x = 40
meaning that AC = 40


So there are two possibilities:
Either AC = 50 or AC = 40
depending on which two sides are equal of this isosceles triangle.


Currently there isn't enough information to determine which of those values is the correct AC length.
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