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
Answer: 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
Answer: 459/16 cubic mm