Question 258857
Area of a rectangle = Length * Width

Given: Area = 108cm^2
Ratio = 3:4  

The equation: {{{(3*X) * (4*X) = 108}}}
Simplify the equation
{{{12*X^2 = 108}}} Divide by sides by 12
{{{X^2 = 9}}} Take the square root of both sides
{{{X = 3}}}

So using the ration of 3:4 and our value of X
The width of the retangle = X * 3
Width = {{{highlight(9cm)}}}
The length of the rectangle = X * 4
Length = {{{highlight(12cm)}}}


You can check the answer by taking {{{9cm * 12cm = 108cm^2}}}
Also if you divide 9 and 12 by 3, you get 3:4