An isosceles trapezoid has a perimeter of 40.8 millimetres. its shorter base measures 1.4 millimetres and its longer base measures 16.6 millimetres. the two remaining sides have the same length; what is that length?

10.6 mm

Step-by-step explanation:

Perimeter (P) is the sum of the sides.  

The trapezoid has 4 sides: the shorter base = 1.4mm

                                             the longer base = 16.6mm

                                             the left side  = x

                                             the right side = x    

P = short base + long base + left side + right side

40.8 = 1.4 + 16.6 + x + x

40.8 = 18 + 2x

21.2 = 2x

10.6 = x

10 * 563.67 = 5636.7

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