Question

the length of rectangle is 3 times width the perimeter is 84 M find the length of the rectangle

Answer 1

given length=3times breadth
l =3b
perimeter =84
perimeter of rectangle =2(l+b)
2(3b+b)=84
2(4b)=84
4b=84/2
4b=42
b=42/4
b=10.5meters
length=3b
l=3(10.5)
l=31.5meters is answer
length of rectangle =31.5meters

Answer 2

Hey mate thank for the question
Hope it helps
Let the width=x
so length=3x
Perimeter=2(l+b)
84=2(x+3x)
84/2=4x
42=4x
x=42/4
x=10.5m
Width=x=10.5m
Length=3x=3*10.5=31.5m