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67.  A square has four congruent (equal) sides so we just multiply the side we have by 4 for the perimeter:

Perimeter = 4(3 1/2) = 14

The area of a square is the side squared,

Area = (3 1/2)² = (7/2)² = 49/4 = 12 1/4

Perimeter 14 in, Area 12 1/4 sq inches.

70.

The volume of a rectangular prism is the product of the three sides lengths,

V = (2 1/8)(6 3/4)(2) = (17/8)(27/4)(2) = (17)(27)/16 = 459/16

459/16 cubic mm

a complex number is a number that can be expressed in the form a + bi, where a and b are real numbers, and i is a solution of the equation x2 = −1. because no real number satisfies this equation, i is called an imaginary number. has no real solution, since the square of a real number cannot be negative.

180 square centimeters

step-by-step explanation: