4. A = 18²/2 = 162 . . . . . . . . . . . . . . . units²
.. P = 4*18/√2 = 36√2 ≈ 50.9 . . . . . units
6. The area of the unshaded rectangle is
.. a = (3√2)*(1√2) = 6
The area of the larger square is
.. A = 4² = 16
The shaded area is the difference of these
.. 16 -6 = 10 . . . . units²
