Congruent Rectangles

🏆Practice congruent rectangles

Congruent rectangles are those that have the same area and the same perimeter. 

Let's look at an exercise as an example: 

Given the rectangles ABCD ABCD and KLMN KLMN , as described in the following scheme:

Given the rectangles

Observe the data that appears in the scheme and determine if they are congruent rectangles.

In the first rectangle we see the following: 

AB=7 AB=7

BC=5 BC=5

P=24 P=24

A=35 A=35

That is, the perimeter is equal to 24 24 and the area, to 35 35 .


In the second rectangle we see the following: 

KL=8 KL=8

LM=4 LM=4

P=24 P=24

A=32 A=32

That is, the perimeter is equal to 24 24 and the area, to 32 32 .

Both rectangles have the same perimeter, but their area is different.

Therefore, they are not congruent.


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Test yourself on congruent rectangles!

einstein

Are the rectangles below congruent?

222333444333

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Exercise with Congruent Rectangles

Exercise 1

Examples and Exercises with Solutions for Congruent Rectangles

Exercise #1

Are the rectangles below congruent?

222333444333

Video Solution

Step-by-Step Solution

We can see that the length is identical in both rectangles: 3=3.

However their widths are not equal, as one is 2 while the other is 4.

Therefore, the rectangles are not congruent.

Answer

No

Exercise #2

Are the rectangles below congruent?

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Video Solution

Step-by-Step Solution

Since there are two pairs of sides that are equal, they also have the same area:

8×4=32 8\times4=32

Therefore, the rectangles are congruent.

Answer

Yes

Exercise #3

Are the rectangles congruent?

222555444AAABBBDDDCCCEEEGGG

Video Solution

Step-by-Step Solution

Note that DC divides AE into two unequal parts.

AC=5 while CE=4

The area of rectangle ABDC is equal to:

5×2=10 5\times2=10

The area of rectangle CDGE is equal to:

4×2=8 4\times2=8

Therefore, the rectangles do not overlap.

Answer

No

Exercise #4

If rectangle A is congruent to rectangle B, the perimeter of both rectangles must be...?

Video Solution

Step-by-Step Solution

By definition congruent rectangles are rectangles that have the same area and the same perimeter. 

Answer

The same.

Exercise #5

Find all the congruent rectangles

5552.52.52.52.52.52.52.52.52.52.52.52.5555AAABBBCCCDDDEEEFFFGGGHHHIIIJJJ33

Video Solution

Step-by-Step Solution

Since JI intersects AH and divides it into two identical parts, we can claim that:

AI=IH=BJ=JG=3 AI=IH=BJ=JG=3

And since it is given that:

AB=HG=5 AB=HG=5

Rectangles ABJI and IJGH are equal and overlapping.

Let's look at rectangle ADEH where AH equals 6, therefore:

AH=DE=6 AH=DE=6

From this it follows that:

AH=CF=DE=6 AH=CF=DE=6

It is also given that:

BC=CD=GF=FE=2.5 BC=CD=GF=FE=2.5

Therefore we can claim that rectangles BCFG and CDEF are equal and overlapping.

Since side BG divides sides HE and AD into two equal parts:

AB=BD=HG=GE=5 AB=BD=HG=GE=5

And since:

AH=BG=DE=6 AH=BG=DE=6 we can claim that rectangles BDEG and ABGH are equal and overlapping.

Answer

ABJIIJGHBCFGCDEFABGHBDEG ABJI\cong IJGH\\BCFG\cong CDEF\\ABGH\cong BDEG

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