Answer:
80 cm
Step-by-step explanation:
The formulas for area and perimeter are ...
A = LW
P = 2(L +W)
When you have length equal to 3 times the width, then ...
A = (3W)W = 3W²
P = 2(3W +W) = 8W
Writing perimeter in terms of area, we have ...
W = √(A/3) . . . . . solve Area formula for W
P = 8√(A/3) . . . . substitute for W in perimeter formula
For the given value of area, the perimeter is ...
P = 8√(300/3) = 80
The perimeter of the rectangle is 80 cm.
