The length of the rectangle = 12 cm
Explanations:Let the area be represented by A
Let the length be represented by L
Let the width be represented by W
The area of the rectangle = 48cm²
A = 48cm²
The length is three times the width
L = 3W
Area = Length x Width
A = LW
48 = 3W(W)
48 = 3W²
W² = 48/3
W² = 16
W = √16
W = 4 cm
L = 3W
L = 3(4)
L = 12 cm
The length of the rectangle = 12 cm
