2b: If x is 2.1, then one side of the rectangle is 2.1, and another is 2.1*5=10.5. Thus, the perimeter is 2*(2.1+10.5)=2*12.6=25.2.
3: One side of the square with side-length three will not be on the outside, so we have 3*3=9 inches perimeter from the square of side-length 3. The square of side-length 6 has 3 from the top side missing from the outer perimeter, because it coincides with a side of the square of side-length three. This square contributes 6*4-3=33 inches. The total perimeter is 33+9=42 inches.
