The area of a right triangle is equal to half the product of the lengths of its legs. Since we know the lengths of one leg and the hypotenuse, we can calculate the length of the other leg using the Pythagorean Theorem. We can use this form:

Setting  and  equal to the lengths of the hypotenuse and the known leg - 13 and 5, respectively:

The area of the above triangle is

The square also has this area. The length of one side of this square is equal to the square root of this, which is .

A rectangle has perimeter ,  the length and  the width. Substitute  and  in the perimeter formula, and simplify.

In inches, the perimeter of the rectangle can be calculated by substituting  in the following formula:

The perimeter is 110 inches.

Now divide by 12 to convert to feet:

This makes the perimeter 9 feet 2 inches, which is between 9 feet and 10 feet.

Let:

The perimeter of a rectangle is , where  is the length and  is the width of the rectangle. The perimeter is known so we can set up an equation in terms of and solve it:

So we can get:

inches

inches

The perimeter of a rectangle is , where  is the length and  is the width of the rectangle. In order to find the perimeter we can substitute the  and  in the perimeter formula:

The length of the rectangle is known, so we can find the width in terms of :

The perimeter of a rectangle is , where  is the length and  is the width of the rectangle.

In order to find the perimeter we can substitute the  and  in the perimeter formula:

Substitute to get and :

The perimeter of a rectangle is  , where is the length and  is the width of the rectangle. So we have:

inches

Now we should divide the perimeter by 12 in order to convert to feet:

 feet

So the perimeter is 7 feet and 6 inches, which is between 7 and 8 feet.

The perimeter of a rectangle is twice the sum of its length and its width; a rectangle with dimensions 55 inches and 15 inches has perimeter 

 inches.

All of the polygons in the choices are regular - that is, all have congruent sides - and all have sidelength two feet, or 24 inches, so we divide 140 by 24 to determine how many sides such a polygon would need to have a perimeter equal to the rectangle. However, 

,

so there cannot be a regular polygon with these characteristics. All of the choices fail, so the correct response is that none are correct.

The area of Mark's lawn is . The amount of grass seed he needs is  pounds.

He has two options.

Option 1: he can buy three fifty-pound bags for 

Option 2: he can buy two fifty-pound bags and four ten-pound bags for 

The first option is the more economical. 

The area of a rectangle is given by multiplying the width times the height. As a formula:

Where:

is the width and is the height. So we can get: