The perimeter of a rectangle is found by multiplying the sum of the length, shown as I, and the width, shown as w, by 2. The length of a certain rectangle is 20. Which
inequality shows that the perimeter of this rectangle is less than 57 units?
A.2 (20+w) > 57
B.2 (20 + w) < 57
C.2 (20) (w) > 57
D.2 (20) (w) < 57

  B.  2(20 + w) < 57

Step-by-step explanation:

Only choices B and D show something "less than 57". Of those, only choice B shows a sum of length and width.

for ex: the reciprocal of 3/4 is 4/3. it is the opposite.

reciprocal definition:

a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2