From a Quadrilateral to a Rectangle - Examples, Exercises and Solutions

Understanding From a Quadrilateral to a Rectangle

Complete explanation with examples

How do we recognize that the quadrilateral in front of us is actually a rectangle?
In two quite simple ways!

First form: angle check

A rectangle is a quadrilateral whose angles are equal to 90o 90^o degrees, if we can prove that this is also the case for our quadrilateral, we can prove that it is a rectangle.

Second form: parallelogram proof and then rectangle proof

This form is a bit more complicated, as it involves two steps.
So, why is it useful?
There are five ways to prove that a quadrilateral is a parallelogram, so many times (depending on the data) it will be easier to prove that the quadrilateral is a parallelogram.
Once we have been able to prove this, we can move on to the next step and prove why this parallelogram is a rectangle.
Remember, a rectangle is a special case of a parallelogram.

A plain rectangle is shown being annotated with geometric properties: right angles at each corner and opposite sides marked as equal in length

Detailed explanation

Practice From a Quadrilateral to a Rectangle

Test your knowledge with 4 quizzes

Given the quadrilateral ABCD so that

AD||BC , AB||CD

Indicate if the quadrilateral is a rectangle.

AAABBBCCCDDD30°60°

Examples with solutions for From a Quadrilateral to a Rectangle

Step-by-step solutions included
Exercise #1

ABCD is a square with sides measuring 4 cm.


Is ABCD a rectangle?

444AAABBBDDDCCC

Step-by-Step Solution

We know that the figure shows a square and that, in a square, every pair of opposite sides are parallel.

We also know that every pair of opposite sides in a rectangle are parallel as well.

Therefore, the quadrilateral ABCD is indeed a rectangle.

Answer:

Yes

Video Solution
Exercise #2

Given the quadrilateral ABCD whereby

AD||BC , AB||CD

Indicate if the quadrilateral is a rectangle.

AAABBBCCCDDD100°

Step-by-Step Solution

In a rectangle, it is known that all angles measure 90 degrees.

Since we know that angle B is equal to 100 degrees, the quadrilateral cannot be a rectangle.

Answer:

No

Video Solution
Exercise #3

It is possible to draw a quadrilateral that is not a rectangle, with the sum of its two adjacent angles equaling 180?

Step-by-Step Solution

Answer:

Yes.

Video Solution
Exercise #4

It is possible to have a rectangle with different angles?

Step-by-Step Solution

Answer:

No

Video Solution
Exercise #5

It is possible to draw a quadrilateral that is not a rectangle and that has two equal opposite sides?

Step-by-Step Solution

Answer:

Yes.

Video Solution

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