Last visit was: 21 Dec 2024, 23:16 It is currently 21 Dec 2024, 23:16

Close

GRE Prep Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Intern
Intern
Joined: 15 Jun 2021
Posts: 23
Own Kudos [?]: 12 [0]
Given Kudos: 3
Send PM
avatar
Intern
Intern
Joined: 04 Aug 2021
Posts: 2
Own Kudos [?]: 4 [1]
Given Kudos: 0
Send PM
Intern
Intern
Joined: 02 Dec 2021
Posts: 19
Own Kudos [?]: 19 [0]
Given Kudos: 11
Send PM
Verbal Expert
Joined: 18 Apr 2015
Posts: 30448
Own Kudos [?]: 36808 [0]
Given Kudos: 26096
Send PM
Re: AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
Expert Reply
schrodinger wrote:
can some one plz explain the of BE?


what does it mean the red part Sir.?

it is unclear
avatar
Intern
Intern
Joined: 26 Jul 2020
Posts: 2
Own Kudos [?]: 2 [1]
Given Kudos: 0
Send PM
Re: AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
1
Let AB=DE=x and
AE=BD=y
Area of triangle ABE=xy/2.

since, BC || DF and BF||CD and BC=CD
so BCFD either square or rhombus
so CF is perpendicular to BD( or AE)
CF||DE and CD||FE
so CF=DE=x
so Area of BCDF=(diagonal1 x diagonal2)/2=xy/2
So Quantity A=Quantiy B
Answer: C
Retired Moderator
Joined: 28 Sep 2020
Posts: 136
Own Kudos [?]: 114 [0]
Given Kudos: 2
Send PM
Re: AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
This is quite interesting:

Since AB=ED and they form right angles with the base AE, then have a rectangle and BD=AE ---------- (1)

Also, one must recognize that parallel lines will form alternate anterior angles and since we have BC=CD, then similarly BF=DF

Traiangles BCD and BFD are equal ---------- (2)

Note that F is the center of the rectangle. Therefore the length CF is equal to AB and ED ---------- (3)

Now the area of triangle ABE = 1/2*AE*AB

The area of the quadrilateral BCDF = BCD+BFD = 2*1/2*CF*BD using findings of (1) and (3), we can replace CF with AB and BD with AE

Answer is (C)

Visualization work best here!
avatar
Intern
Intern
Joined: 17 Jul 2022
Posts: 3
Own Kudos [?]: 2 [0]
Given Kudos: 0
Send PM
Re: AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
There is no enough info to prove ABDE is a square or 30-60-90 for any triangles.

It is easy to prove that 1) BCDF and CDEF are parallelogram, 2) BF = FE (using midsegment).
So within trapezoid BCDE, it is easy to see that area BCDF equal to the area of triangle BDE.
And it is clear and area BDE equal to area ABE
Therefore BCDF = ABE.
Manager
Manager
Joined: 01 Apr 2022
Posts: 65
Own Kudos [?]: 15 [0]
Given Kudos: 79
Send PM
Re: AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
pranab223 wrote:
pclawong wrote:
explain please



Now we need the area of triangle ABE = Area of square ABDE - area of triangle BDE - area of triangle DEF


Sir, can you explain this part?
avatar
Intern
Intern
Joined: 02 Aug 2022
Posts: 1
Own Kudos [?]: 1 [1]
Given Kudos: 7
Send PM
AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
1
No disrespect but I found all the solutions unnecessarily complicated or just invalid hence thought of posting my approach

From the given statements AB=DE, AB||DE, AB perpendicular AE
we can conclude that quad ABDE is a rectangle, and hence AE=BD

From the given statements BE||CD, BC||DF, BC=CD
we can conclude that quad BCDF is a rhombus

Lets say the diagonals of the rhombus BCDF bisect each other at point M on line BD

From above statement and property - the diagonals of a rhombus are perpendicular bisectors of one another,
we can conclude that CM=FM

From above statement if we extend line CF to line AE such that it intersects at point N
we conclude that FN is perpendicular bisector of AE

Quad ABDE is a rectangle and the diagonals bisect at a point equidistant from the opposite sides of the rectangle
from this we conclude that MF=NF

Thus CM=FM=FN,
CF = CM + MF
MN = MF + FN
MN = AB
AB=CF

Area of rhombus is half the product of its diagonals = 1/2*CF*BD

Area of triangle is half the product of its base and height = 1/2*AB*AE = 1/2*CF*BD

Hence, the answer is option C
Manager
Manager
Joined: 16 Dec 2019
Posts: 190
Own Kudos [?]: 132 [0]
Given Kudos: 59
Send PM
Re: AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
Official solution for this question please
Verbal Expert
Joined: 18 Apr 2015
Posts: 30448
Own Kudos [?]: 36808 [1]
Given Kudos: 26096
Send PM
Re: AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
1
Expert Reply
OE

Because of the various parallel and equal length constraints, you can see that quadrilateral BCD F is a rhombus with side lengths equal to half diagonal BE. In fact, the whole shape can be split into 10 identical right triangles, as shown:

Attachment:
GRE (4).jpg
GRE (4).jpg [ 37.97 KiB | Viewed 1048 times ]


A is The area of triangle ABE - 4 small triangles

B is The area of quadrilateral BCDF - 4 small triangles

C is the answer
Intern
Intern
Joined: 26 Dec 2023
Posts: 44
Own Kudos [?]: 16 [0]
Given Kudos: 4
Send PM
Re: AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
Note on strategy: If you were running out of time and wanted to make a guess, you could make a reasonable guess here.

The amount of information they provide suggests that the figure is actually drawn to scale. If you see this, you can visualize the two areas, by seeing how many triangles of the same size they have in common. It looks basically equal to my eye, so I guessed C.

Most of the time you can't make visual guesses like this, but the amount of info made me think, there is really no way for me to change how this looks without violating one of the conditions they gave me.
avatar
Intern
Intern
Joined: 01 Jul 2024
Posts: 2
Own Kudos [?]: 0 [0]
Given Kudos: 3
Send PM
Re: AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
pranab223 wrote:
pranab01 wrote:
pclawong wrote:
explain please


This is a tough ques, let me try


All queries are welcome!!!


Based on the above solution if the reasoning is correct then we can also have the diagram (attached)

Now if we divide to 10 small triangles (considering all the assumption given and proven in previous response)

Then Area of Triangle = ABE = sum of 4 triangles

and Area of quadrialteral = sum of 4 triangles

This also led to option C.


Kindly let me know if my reasoning are correct.

Thanks in advance. and all queries are welcome

I think it's a good quick reasoning, I did something similar (not exactly same) to get same answer.
Prep Club for GRE Bot
Re: AB = DE, BC = CD, BE is parallel to CD, and BC is par [#permalink]
   1   2 
Moderators:
GRE Instructor
88 posts
GRE Forum Moderator
37 posts
Moderator
1115 posts
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne