The sum of the widths is \(\displaystyle 2w\)and since the width is half the length, each length is \(\displaystyle 2w\). Since there are 2 lengths we get a total perimeter of \(\displaystyle 6w\).

The best way to see that 750 feet of fence are needed is to look at this augmented diagram.

Note that two of the sides are extended to form a smaller rectangle whose sides can be deduced by subtraction. Since opposite sides of a rectangle are congruent, this allows us to fill in the two missing sidelengths of the original figure.

Now add: \(\displaystyle 150+110+70+115+80+225 = 750 \textrm{ft}\)

The perimeter of a rectangle is the sum of the length and the width, multiplied by 2:

\(\displaystyle 2 (12.6 + 6.4) = 2 \cdot 19 = 38\)

The rectangle has a perimeter of 38 centimeters.

The perimeter of a rectangle can be calculated by multiplying two by the sum of the length and width of the rectangle.

\(\displaystyle 2\left ( 7 \frac{1}{2} +5 \frac{3}{5} \right )\)

\(\displaystyle =2 \left (\frac{7 \cdot 2 + 1}{2} + \frac{5\cdot 5 + 3}{5} \right )\)

\(\displaystyle = 2 \left (\frac{15}{2} + \frac{28}{5} \right )\)

\(\displaystyle = 2 \left (\frac{15 \times 5}{2 \times 5} + \frac{2 \times28}{2 \times5} \right )\)

\(\displaystyle = 2 \left (\frac{75}{10} + \frac{56}{10} \right ) = \frac{2}{1} \cdot \frac{131}{10} = \frac{131}{5} = 26 \frac{1}{5}\)

The perimeter of the rectangle is \(\displaystyle 26 \frac{1}{5}\) inches.

Since opposite sides of a rectangle have the same measure, the missing sidelengths can be calculated as in the diagram below:

The sidelengths of the green polygon can now be added to find the perimeter:

\(\displaystyle P= 35 +60 + 35 + 15 + 20 + 30 + 20 + 15 = 230\)

The perimeter of a rectangle is the sum of its sides.

The sum of the widths is \(\displaystyle 2w\) and since the width is one-third of the length, each length is \(\displaystyle 3w\). Since there are \(\displaystyle 2\) lengths we get a total of \(\displaystyle 6w\). Widths + lengths = \(\displaystyle 2w + 6w = 8w\)

\(\displaystyle \Delta ABC\) is equilateral, so \(\displaystyle AC = AB = 25\).

Also, since opposite sides of a rectangle are congruent, 

\(\displaystyle DE = AC = 25\) and \(\displaystyle AE = CD = 40\)

The perimeter of Rectangle \(\displaystyle ACDE\) is 

\(\displaystyle AC + CD +DE + AE = 25 + 40 + 25 + 40 = 130\)

150 hectares is equal to \(\displaystyle 150 \times 10,000 = 1,500,000\) square meters.

The width of this land is 1.2 kilometers, or \(\displaystyle 1.2 \times 1,000 =1,200\) meters. Divide the area by the width to get:

\(\displaystyle 1,500,000 \div 1,200 = 1,250\) meters

The perimeter of the land is 

\(\displaystyle 2 \left ( 1,200 + 1,250\right ) = 4,900\) meters, or \(\displaystyle 4,900 \div 1,000 = 4.9\) kilometers.

\(\displaystyle l=2w=2(4)=8\)

\(\displaystyle P=l+w+l+w=2l+2w=2(8)+2(4)=16+8=24\)

The perimeter of a rectangle is simply the sum of the four sides:

\(\displaystyle 1000+1000+100+100=2200\; meters\)