The length of a rectangle is four times its width. If the
area is 100 meters squared,
what is the length of the
rectangle?

We know that the area of any rectangle is length times width. The perimeter is the sum of twice the length and twice the width.

Let width = x
Let length = 4x
Area = 100m2

Next, we can write an equation using these variables and formula for area.

4x2 = 100

x2 = 25

x = -5 and x = 5

Since the dimensions cannot be negative, we accept the positive value:

x = 5

Next, we can substitute this value of x into the variables.

width = 5 m
length = 20 m

Finally, we can find the perimeter by plugging in these dimensions into the perimeter formula,

Perimeter = 2(5 m) + 2(20 m)
= 10 m + 40 m
= 50 m