So if we say the width is x, and the length is x+4, we know that 2(x+4) + 2x =16.
Open up the parenthesis with the distributive property, and you get 2x + 8 + 2x = 16.
Subtract 8 from both sides.
2x + 2x = 8
Or
4x = 8
/4 /4
x = 2
So therefore, since the width is x, then the width is 2. The length is x+4, or 6.
The area is length times width.
2×6 = 12
So the area of the rectangle is 12 square units.