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counting and probability senior

Problem

How many non-congruent triangles with perimeter have integer side lengths?
(A)
(B)
(C)
(D)
Solution
By the triangle inequality, no side may have a length greater than the semiperimeter, which is . Since all sides must be integers, the largest possible length of a side is . Therefore, all such triangles must have all sides of length , , or . Since , at least one side must have a length of . Thus, the remaining two sides have a combined length of . So, the remaining sides must be either and or and . Therefore, the number of triangles is .
Final answer
B