Answer:
Option C. 12 by 15
Step-by-step explanation:
Let the length be L
Let the width be w
Area of rectangle = L x w
Perimeter of rectangular = 2 (L + w)
From the question given,
A = 180
P = 54
180 = L x w (1)
54 = 2(L + w) (2)
From equation (2),
54 = 2(L + w)
Divide both side by the 2
54/2 = L + w
27 = L + w
L = 27 — w (3)
Substituting the value of L into equation (1), we have:
180 = L x w
180 = w(27 — w)
180 = 27w — w^2
Rearrange the expression
w^2 — 27w + 180 = 0 (4)
Solving by factorization method:
Multiply the first term (i.e w^2) with the last term (i.e 180). This gives 180w^2. Now find two factors of 180w^2, such that their sum will result to the second (i.e —27w). These factors are —12w and —15w.
Now, substitute these factors (—12w and —15w) into equation (4)
w^2 — 27w + 180 = 0
w^2 — 12w —15w + 180 = 0
w(w — 12) — 15(w — 12) =0
(w — 12) (w — 15) = 0
w = 12 or w = 15.
Substituting the value of w into equation (3)
L = 27 — w
When w = 12
L = 27 — 12 = 15
When w = 15
L = 27 — 15 = 12
Since the length is longer than the width, the length is 15 and the width is 12.
Therefore the dimensions is 12 x 15
