Answer:
Length=45cm Breadth=15cm
Explanation:
Breadth=x
Hence length=3x
Perimeter=120cm
Perimeter of rectangle= 2×(l+b)
120=2×(3x+x)
120/2=4x
4x=60
x=60/4
x=15
Hence breadth comes out to be 15cm, hence length will be 3×15=45cm
Hope this helps you. Have a nice day buddy!