Answer:
221 mm
Step-by-step explanation:
The dimension 74 mm is presumed to mean that the actual length could be anywhere in the interval [73.5, 74.5). So, the minimum perimeter is ...
3 × 73.5 = 220.5 ≈ 221 . . . millimeters
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The perimeter of an equilateral triangle is 3 times the side length, since all three sides of the triangle are the same length.
Polynomials are not closed under division. When you divide polynomials it is possible to get quotients with negative exponents or with fractions that have exponents in the denominator, and neither of these could be included in polynomials.