To find the area of a rectangle, we will use the following formula:

$\displaystyle A = l \cdot w$

where l is the length and w is the width of the rectangle.  

Now, we know the length of the rectangle is 16in.  We also know the width is half of the length.  Therefore, the width is 8in.

Knowing this, we can substitute into the formula.  We get

$\displaystyle A = 16\text{in} \cdot 8\text{in}$

$\displaystyle A = 128\text{in}^2$

To find the area of a rectangle, we will use the following formula:

$\displaystyle A = l \cdot w$

where l is the length and w is the width of the rectangle.  

Now, given the rectangle

we can see the length is 11in and the width is 5in.  Knowing this, we can substitute into the formula.  We get

$\displaystyle A = 11\text{in} \cdot 5\text{in}$

$\displaystyle A = 55\text{in}^2$

To find the area of a rectangle, we will use the following formula:

$\displaystyle A = l \cdot w$

where l is the length and w is the width of the rectangle.  

Now, we know the width of the rectangle is 4in.  We also know the length of the rectangle is two times the width.  Therefore, the length is 8in.  So, we get

$\displaystyle A = 8\text{in} \cdot 4\text{in}$

$\displaystyle A = 32\text{in}^2$

In order to determine how much fence Dennis will need, we must find the perimeter of his property, which can be found using the formula $\displaystyle \small \small 2W+ 2L$. When we plug $\displaystyle \small 2\ mi$ in the $\displaystyle \small W$ and $\displaystyle \small 3\ mi$ in for $\displaystyle \small L$, we find that Dennis needs $\displaystyle \small 10\ mi$ of fence to surround his property.

$\displaystyle \small 2(2\ mi) + 2(3\ mi) = 10\ mi$

Add the length and the height, then multiply the sum by two:

$\displaystyle (11 + 18) \times 2 = 29 \times 2 = 58$

The rectangle has a perimeter of 58 inches.

Use the following formula, substituting $\displaystyle L = 30, W = 15$ :

$\displaystyle A = 2 (L + W)$

$\displaystyle A = 2 (30 + 15) = 2 \times 45 = 90 \textrm{ in}$

Now, divide this by 12 to convert inches to feet.

$\displaystyle \frac{90}{12} = 7 \textrm{ R }6$

6 inches make half of a foot, so this means the perimeter is $\displaystyle 7 \frac{1}{2}$ feet.

The perimeter of a shape is the sum of all its sides. To find the perimeter of a rectangle, one can use the formula listed above, $\displaystyle \small \left ( P= 2l+2w\right )$, since a rectangle has opposite sides of equal length.

The length of the rectangle is $\displaystyle \small 7$:

$\displaystyle \small 2\times7=14$

The width of the rectangle is $\displaystyle \small 4$:

$\displaystyle \small 4\times2=8$.

$\displaystyle \small 14+8=22$

Therefore, the perimeter is $\displaystyle \small 22$.  

$\displaystyle P=2(l+w)=2(5+3)=2(8)=16$

The perimeter of a rectangle is equal to the sum of all its sides. The formula for finding the perimeter of a rectangle is $\displaystyle P= 2(l+w)$. 

The length of the rectangle is eight, and the width is five; $\displaystyle 8+5=13$.

$\displaystyle 13\times2=26$

Therefore, the perimeter of the rectangle is $\displaystyle 26$.

The perimeter is calculated by adding up all the sides of the rectangle—in this case,

$\displaystyle 6+6+4+4=20$

So the perimeter is $\displaystyle 20$ feet.