Answer:
B. 27 < AB < 81
Step-by-step explanation:
The triangle inequality requires that the length of any given side of a triangle be greater than the difference and less than the sum of the other two sides.
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application
54 -27 < AB < 54 +27
27 < AB < 81
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Additional comment
Some versions of the triangle inequality allow the "or equal to" case.
27 ≤ AB ≤ 81
Apparently, the one used here does not.
If the sum of the two short sides is equal to the long side, the "triangle" looks like a line segment. Its altitude and area are zero.
