# SSAT Elementary Level Math : How to find the perimeter of a rectangle

## Example Questions

### Example Question #381 : Rectangles

What is the perimeter of the rectangle?

Explanation:

To find the perimeter of this rectangle, add all four sides together. Even though we are not given the length of all four sides, we know that opposites sides of a rectangle are always equal.

### Example Question #11 : How To Find The Perimeter Of A Rectangle

Give the perimeter of the rectangle in millimeters.

Explanation:

Use the following formula for the perimeter, substituting the two side lengths,  :

Since there are 1,000 millimeters in 1 meter, multiply the answer by 1,000:

### Example Question #12 : How To Find The Perimeter Of A Rectangle

What is the perimeter of the rectangle?

Explanation:

To find the perimeter of this rectangle, add all four sides together. Even though we are not given the length of all four sides, we know that opposite sides of a rectangle are always equal.

### Example Question #11 : How To Find The Perimeter Of A Rectangle

How many sides does a rectangle have?

5

2

1

3

4

4

Explanation:

A rectangle is a shape with 4 sides.  The opposite sides have equal lengths.

### Example Question #13 : How To Find The Perimeter Of A Rectangle

What is the perimeter of the above rectangle?

Explanation:

To find the perimeter of the rectangle, add all four sides together. Even though we are not given the length of all four sides, we know that opposite sides are always equal.

### Example Question #16 : How To Find The Perimeter Of A Rectangle

What is the perimeter of the blue rectangle?

Explanation:

To find the perimeter of the rectangle, add all four sides together. Even though we are not given the length of all four sides, we know that opposite sides are always equal.

### Example Question #13 : How To Find The Perimeter Of A Rectangle

How many feet of fence do you need to surround the rectangular area in front of the house?

Explanation:

In order to figure out how many feet of fence you need, add up all of the segments that are going to be fenced.  Thus, .  Remember, you will not need to put fence where the house is.

### Example Question #14 : How To Find The Perimeter Of A Rectangle

A rectangle has sides of lengths  and . What is its perimeter?

Explanation:

Since a rectangle has two sets of equal sides, the perimeter is the sum of twice each of the two sides given.  and , which is the answer.

### Example Question #19 : How To Find The Perimeter Of A Rectangle

If a rectangle has a perimeter of  units, and one of its sides is of length , what are the lengths of its other three sides?

, and

, and

, and

, and

, and

, and

Explanation:

Since rectangles have two sets of equal sides, and one side is of length , there must be another side of length . Since we know the total perimeter of the rectangle, we can get the length of the two remaining sides by subtracting the two known side lengths from the total perimeter. , and since the rectangle must have another set of equal sides, we must split  into two equal parts. Therefore, the last two sides must be  and . This means the rectangle's other three sides must be , , and .

### Example Question #20 : How To Find The Perimeter Of A Rectangle

Madison would like to buy a rug to cover the whole floor in her new room. Her room is in the shape of a rectangle and has a perimeter of  feet. She measured and one side of her room is  feet long. Which of the following rug dimensions would best fit Madison's room?

Explanation:

The perimeter is the measurements of all four sides of a square or rectangle. We can use the following formula to solve the problem:

We already know that one side is 15 ft and that the total perimeter is 76 ft, so we can plug those numbers into the formula.

We can subtract 30 from both sides of the equation.

Now we are left with:

We can divide both sides by 2 to find the width of the room.

Therefore, the lengths of the other two sides of the room are 23 ft.

To check to see if our answer is correct we can add the four sides of the room:

This equals 76! (The perimeter of the room in the problem.)

Madison should buy a rug that is 15 ft. by 23 ft.