Lets suppose:

Width = x

So

Length = 4x

We are given that:

perimeter=70

the formula for the perimeter of a rectangle is :

Perimeter=2(L+W)

so plugging in the values:

p=2(L+W)

70=2(X+4x)

Expanding:

70=2x+8x

Adding:

70=10x

Dividing:

x=70/10

x=7

Hence the width is 7

To find the length:

L=4x

L=4(7)

Multiplying:

L=28

Hence the length is 28

The formula for the area of a rectangle is:

Area=L*W

So:

Area=28*7

area=196

So the area is 196

Width = x

So

Length = 4x

We are given that:

perimeter=70

the formula for the perimeter of a rectangle is :

Perimeter=2(L+W)

so plugging in the values:

p=2(L+W)

70=2(X+4x)

Expanding:

70=2x+8x

Adding:

70=10x

Dividing:

x=70/10

x=7

Hence the width is 7

To find the length:

L=4x

L=4(7)

Multiplying:

L=28

Hence the length is 28

The formula for the area of a rectangle is:

Area=L*W

So:

Area=28*7

area=196

So the area is 196