a, b, c - sides of a triangle
a + b > c
a + c > b
b + c > a
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We have a = 18 and b = 17. Substitute:
18 + 17 > c
35 > c → c < 35
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18 + c > 17 subtract 18 from both sides
c > -1
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17 + c > 18 subtract 17 from both sides
c > 1
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c < 35 and c > -1 and c > 1.
Therefore 1 < c < 35
Answer: The smallest possible whole number length of third side is 2.