How to find the length of the side of a rectangle
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Math › How to find the length of the side of a rectangle

Note: Figure NOT drawn to scale
The above figure shows Rhombus .
Which is the greater quantity?
(a)
(b)
(a) and (b) are equal
It is impossible to determine which is greater from the information given
(b) is the greater quantity
(a) is the greater quantity
Explanation
The opposite sides of a parallelogram - a rhombus included - are congruent, so
.
Also, Quadrilateral form a rectangle; since
and
, it follows that
, and, similarly,
. Therefore,
, and
The two rectangles shown below are similar. What is the length of EF?

5
6
8
10
Explanation
When two polygons are similar, the lengths of their corresponding sides are proportional to each other. In this diagram, AC and EG are corresponding sides and AB and EF are corresponding sides.
To solve this question, you can therefore write a proportion:
AC/EG = AB/EF ≥ 3/6 = 5/EF
From this proportion, we know that side EF is equal to 10.
If the area of a rectangle is , and the length of the rectangle is
, what is the width of the rectangle?
Explanation
Recall how to find the area of a rectangle.
We can divide both sides by the length to find the width.
Now, plug in the information from the question.
If the area of a rectangle is , and the length of the rectangle is
, what is the width of the rectangle?
Explanation
Recall how to find the area of a rectangle.
We can divide both sides by the length to find the width.
Now, plug in the information from the question.
If the perimeter of a rectangle is and the length of the rectangle is
, what is the width of the rectangle?
Explanation
Recall how to find the perimeter of a rectangle.
We can then manipulate this equation to find the width.
Now, plug in the information given by the question to find the width.
A rectangle has a width of 5 meters. Its length is 2.5 times the width. What is the length of the long side and the total area of this rectangle?
None of these.
Explanation
"2.5 times the width" is equivalent to 2.5w. The length of the long side is .
The area is
A rectangle has a perimiter of 36 inches and a length of 12 inches. What is the width of the rectangle in inches?
Explanation
To find the width, multiply the length that you have been given by 2, and subtract the result from the perimeter. You now have the total length for the remaining 2 sides. This number divided by 2 is the width.
If the perimeter of a rectangle is , and the length of the rectangle is
, what is the width of the rectangle?
Explanation
Recall how to find the perimeter of a rectangle.
We can then manipulate this equation to find the width.
Now, plug in the information given by the question to find the width.
A rectangle is x inches long and 3x inches wide. If the area of the rectangle is 108, what is the value of x?
6
3
12
4
8
Explanation
Solve for x
Area of a rectangle A = lw = x(3x) = 3x2 = 108
x2 = 36
x = 6
Find the length of a recangle given area is 10 and width is 2.
Explanation
To solve, simply use the formula for the area of a rectangle and solve for length.