Equilateral triangle ABC has a perimeter of 96 millimeters. A perpendicular bisector is drawn from angle cap A to side line segment BC at point cap m What is the length of line segment MC ?

An equilateral triangle has three equal sides, so each side is 96 ÷ 3 = 32 mm. In an equilateral triangle, the perpendicular bisector from vertex A meets BC at its midpoint M. Therefore, MC is half of BC: 32 ÷ 2 = 16 mm. The correct choice is 16 mm.

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