Last visit was: 24 Apr 2026, 12:37 It is currently 24 Apr 2026, 12:37
Close
GMAT 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 GMAT 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
User avatar
sujoykrdatta
Joined: 26 Jun 2014
Last visit: 23 Apr 2026
Posts: 587
Own Kudos:
1,191
 [2]
Given Kudos: 14
Status:Mentor & Coach | GMAT Q51 | CAT 99.98
GMAT 1: 740 Q51 V39
Expert
Expert reply
GMAT 1: 740 Q51 V39
Posts: 587
Kudos: 1,191
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
sujoykrdatta
Joined: 26 Jun 2014
Last visit: 23 Apr 2026
Posts: 587
Own Kudos:
Given Kudos: 14
Status:Mentor & Coach | GMAT Q51 | CAT 99.98
GMAT 1: 740 Q51 V39
Expert
Expert reply
GMAT 1: 740 Q51 V39
Posts: 587
Kudos: 1,191
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Asad
sujoykrdatta
Asad
In the diagram to the below, the value of \(x\) is closest to which of the following?

A) \(2+√2\)
B) \(2\)
C) \(√3\)
D) \(√2\)
E) \(1\)



Let us drawn AP perpendicular to BC as shown below:

Attachment:
111.JPG

In triangle APC: Angle ACP = Angle CAP = \(45^o\)

=> It is a 45-45-90 triangle

=> AP = PC = AC/\(\sqrt{2}\) = \(x/\sqrt{2}\)

=> BP = \(x - x/\sqrt{2}\)

In right triangle ABP: \(AB^2 = AP^2 + BP^2\)

=> \(2 = (x/\sqrt{2})^2 + (x - x/\sqrt{2})^2\)

=> \(2 = x^2/2 + x^2 + x^2/2 - 2x^2/\sqrt{2}\)

=> \(2 = x^2 * (2 - \sqrt{2})\)

=> \(x^2 = 2/(2 - \sqrt{2}) = ~ 2/0.6 = 3.33\) (approximately)

=> \(x = \sqrt{3.33} = 1.8\)

=> Closest value = 2

Answer B

\(√3.33\) = \(1.43\)
1.43 is closed to \(√3\). So the correct choice is C, actually.


How is \(√3.33\) = \(1.43\)?

\(1.4^2 = 1.96\)
\(1.5^2 = 2.25\)
\(1.8^2 = 3.24\)
avatar
suchita2409
Joined: 11 May 2019
Last visit: 22 Jun 2021
Posts: 165
Own Kudos:
Given Kudos: 296
Posts: 165
Kudos: 125
Kudos
Add Kudos
Bookmarks
Bookmark this Post
IMO ans is 1

Its an iso . triangle bcoz it has 2 equal sides.
One of the angle is 45 so the other one is also 45( same sides)

Its a 45 45 90 triangle.
The sides of 45 45 90 triangles are in ratio of 1 1 root 2.
Hypo is root 2 therefore x is 1

Posted from my mobile device
User avatar
AnirudhaS
User avatar
LBS Moderator
Joined: 30 Oct 2019
Last visit: 25 Jun 2024
Posts: 778
Own Kudos:
Given Kudos: 1,575
Posts: 778
Kudos: 887
Kudos
Add Kudos
Bookmarks
Bookmark this Post
sujoykrdatta
Asad
In the diagram to the below, the value of \(x\) is closest to which of the following?

A) \(2+√2\)
B) \(2\)
C) \(√3\)
D) \(√2\)
E) \(1\)



Let us drawn AP perpendicular to BC as shown below:

Attachment:
111.JPG

In triangle APC: Angle ACP = Angle CAP = \(45^o\)

=> It is a 45-45-90 triangle

=> AP = PC = AC/\(\sqrt{2}\) = \(x/\sqrt{2}\)

=> BP = \(x - x/\sqrt{2}\)

In right triangle ABP: \(AB^2 = AP^2 + BP^2\)

=> \(2 = (x/\sqrt{2})^2 + (x - x/\sqrt{2})^2\)

=> \(2 = x^2/2 + x^2 + x^2/2 - 2x^2/\sqrt{2}\)

=> \(2 = x^2 * (2 - \sqrt{2})\)

=> \(x^2 = 2/(2 - \sqrt{2}) = ~ 2/0.6 = 3.33\) (approximately)

=> \(x = \sqrt{3.33} = 1.8\)

=> Closest value = 2

Answer B
Hi sir, I think its closer to \(\sqrt{3}\).
\(\sqrt{3}\)=1.7. Your answer is 1.8. It is closer to 1.7 than 2.

Anyways my working is as follows -
\(2 = (\frac{x}{\sqrt{2}})^2 + (x - \frac{x}{\sqrt{2}})^2\)
\(or, 2 = 2x^2 -\frac{2x^2}{\sqrt{2}}\)
\(or, 1 = x^2 - \frac{x^2}{\sqrt{2}}\)
\(or, x^2 = \frac{\sqrt{2}}{(\sqrt{2}-1)}\)
\(or, x^2 = 1.4/0.4 = 3 (approx)\)
\(or, x = \sqrt{3}\)
User avatar
sujoykrdatta
Joined: 26 Jun 2014
Last visit: 23 Apr 2026
Posts: 587
Own Kudos:
Given Kudos: 14
Status:Mentor & Coach | GMAT Q51 | CAT 99.98
GMAT 1: 740 Q51 V39
Expert
Expert reply
GMAT 1: 740 Q51 V39
Posts: 587
Kudos: 1,191
Kudos
Add Kudos
Bookmarks
Bookmark this Post
AnirudhaS
sujoykrdatta
Asad
In the diagram to the below, the value of \(x\) is closest to which of the following?

A) \(2+√2\)
B) \(2\)
C) \(√3\)
D) \(√2\)
E) \(1\)



Let us drawn AP perpendicular to BC as shown below:

Attachment:
111.JPG

In triangle APC: Angle ACP = Angle CAP = \(45^o\)

=> It is a 45-45-90 triangle

=> AP = PC = AC/\(\sqrt{2}\) = \(x/\sqrt{2}\)

=> BP = \(x - x/\sqrt{2}\)

In right triangle ABP: \(AB^2 = AP^2 + BP^2\)

=> \(2 = (x/\sqrt{2})^2 + (x - x/\sqrt{2})^2\)

=> \(2 = x^2/2 + x^2 + x^2/2 - 2x^2/\sqrt{2}\)

=> \(2 = x^2 * (2 - \sqrt{2})\)

=> \(x^2 = 2/(2 - \sqrt{2}) = ~ 2/0.6 = 3.33\) (approximately)

=> \(x = \sqrt{3.33} = 1.8\)

=> Closest value = 2

Answer B
Hi sir, I think its closer to \(\sqrt{3}\).
\(\sqrt{3}\)=1.7. Your answer is 1.8. It is closer to 1.7 than 2.

Anyways my working is as follows -
\(2 = (\frac{x}{\sqrt{2}})^2 + (x - \frac{x}{\sqrt{2}})^2\)
\(or, 2 = 2x^2 -\frac{2x^2}{\sqrt{2}}\)
\(or, 1 = x^2 - \frac{x^2}{\sqrt{2}}\)
\(or, x^2 = \frac{\sqrt{2}}{(\sqrt{2}-1)}\)
\(or, x^2 = 1.4/0.4 = 3 (approx)\)
\(or, x = \sqrt{3}\)


Yes obviously :roll:
I don't know what came of me :|
Must have not seen that option of root3 at all! :-D - corrected that - thanks

Posted from my mobile device
Kudos
Add Kudos
Bookmarks
Bookmark this Post
sujoykrdatta
Asad
sujoykrdatta



Let us drawn AP perpendicular to BC as shown below:

Attachment:
111.JPG

In triangle APC: Angle ACP = Angle CAP = \(45^o\)

=> It is a 45-45-90 triangle

=> AP = PC = AC/\(\sqrt{2}\) = \(x/\sqrt{2}\)

=> BP = \(x - x/\sqrt{2}\)

In right triangle ABP: \(AB^2 = AP^2 + BP^2\)

=> \(2 = (x/\sqrt{2})^2 + (x - x/\sqrt{2})^2\)

=> \(2 = x^2/2 + x^2 + x^2/2 - 2x^2/\sqrt{2}\)

=> \(2 = x^2 * (2 - \sqrt{2})\)

=> \(x^2 = 2/(2 - \sqrt{2}) = ~ 2/0.6 = 3.33\) (approximately)

=> \(x = \sqrt{3.33} = 1.8\)

=> Closest value = 2

Answer B

\(√3.33\) = \(1.43\)
1.43 is closed to \(√3\). So the correct choice is C, actually.


How is \(√3.33\) = \(1.43\)?

\(1.4^2 = 1.96\)
\(1.5^2 = 2.25\)
\(1.8^2 = 3.24\)
My calculator gave me wrong info (value of root 3.33). I was convinced with that wrong value (1.43) because i already know that the correct choice is C.

Edited the first comment..

Posted from my mobile device
avatar
Jokertrap
Joined: 12 Feb 2020
Last visit: 17 Sep 2024
Posts: 3
Own Kudos:
2
 [1]
Given Kudos: 53
Posts: 3
Kudos: 2
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I do not understand this question. When x and x are the same lengths, their respective angles have to have the same degree, right ? so i do not understand how anyonecan say this is a 45 - 45 - 90 triangle. If this was true root 2 has to be the longest side, so that the angles of 45 and 45 are respective to the two x.

In this case side root 2 faces the angle 45 so the angles for x are 135/2, so you can not use the pythagorean theorem to calculate the sides?
User avatar
Fdambro294
Joined: 10 Jul 2019
Last visit: 20 Aug 2025
Posts: 1,331
Own Kudos:
Given Kudos: 1,656
Posts: 1,331
Kudos: 772
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I believe that the question was created by Manhattan Prep to illustrate strategic guessing (I could be wrong, it was a while ago). Also, since we are estimating, we can make some approximate guesses.

I’m a triangle, the sides of a triangle are, in a sense, proportional to the angles of the triangle. The sides are in fact in a constant proportion to the Sine of each angle’s degree measure - the angle opposite each Side

Side a / (Sin Angle Opp a) = Side b / (Sin Angle Opp b) = Side c / (Sin Angle Opp c)

(1st) given we have an isosceles triangle, the other 2 angle measures both equal = (135/2) = 67.5 degrees


(2nd) The “Sine” Proportion can be taken. For each side and its opposite angle, the following proportion holds true:

Sqrt(3) / (Sine 45 deg.) = (X) / (Sine 67.5 deg.) = (X) / (Sine 67.5 deg.)


The Sine of 45 degrees = (1) / (sqrt(2))

We can use the Sine of 60 degrees to approximate the Sine of 67.5 degrees, since it easier to find and since 60 degrees is close to 67.5 degrees

The sine of 60 degrees = sqrt(3) / 2


Substituting we have:

[ sqrt(2) ] / [ 1/sqrt(2) ] = [ x ] / [ sqrt(3) / 2]

In the right hand side of the equation, the square root of 2 squared = 2——-you are left with:


2 = (2x) / (sqrt(3))

—cancel the 2 in the NUM on each side of the equation—

1 = X / (sqrt(3))

-cross multiply-

X = sqrt(3)

Since this is only an approximation and not the actual value or X, I suspect there are other ways to estimate the answer. It’s too coincidental that the estimate found happened to be the exact value of the correct answer approximation.

Posted from my mobile device
User avatar
sujoykrdatta
Joined: 26 Jun 2014
Last visit: 23 Apr 2026
Posts: 587
Own Kudos:
Given Kudos: 14
Status:Mentor & Coach | GMAT Q51 | CAT 99.98
GMAT 1: 740 Q51 V39
Expert
Expert reply
GMAT 1: 740 Q51 V39
Posts: 587
Kudos: 1,191
Kudos
Add Kudos
Bookmarks
Bookmark this Post
sujoykrdatta
Asad
In the diagram to the below, the value of \(x\) is closest to which of the following?

A) \(2+√2\)
B) \(2\)
C) \(√3\)
D) \(√2\)
E) \(1\)



Let us drawn AP perpendicular to BC as shown below:

Attachment:
The attachment 111.JPG is no longer available

In triangle APC: Angle ACP = Angle CAP = \(45^o\)

=> It is a 45-45-90 triangle

=> AP = PC = AC/\(\sqrt{2}\) = \(x/\sqrt{2}\)

=> BP = \(x - x/\sqrt{2}\)

In right triangle ABP: \(AB^2 = AP^2 + BP^2\)

=> \(2 = (x/\sqrt{2})^2 + (x - x/\sqrt{2})^2\)

=> \(2 = x^2/2 + x^2 + x^2/2 - 2x^2/\sqrt{2}\)

=> \(2 = x^2 * (2 - \sqrt{2})\)

=> \(x^2 = 2/(2 - \sqrt{2}) = ~ 2/0.6 = 3.33\) (approximately)

=> \(x = \sqrt{3.33} = 1.8\)

=> Closest value = \(\sqrt{3}\)

Answer C

For some reason the image is not visible ... Uploading here once more:

Attachment:
Screenshot_20210506-145136.jpg
Screenshot_20210506-145136.jpg [ 38.57 KiB | Viewed 4757 times ]

Hope this helps.
User avatar
MBAB123
Joined: 05 Jul 2020
Last visit: 30 Jul 2023
Posts: 528
Own Kudos:
Given Kudos: 150
GMAT 1: 720 Q49 V38
WE:Accounting (Accounting)
Products:
GMAT 1: 720 Q49 V38
Posts: 528
Kudos: 319
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I had no idea how to solve this in a methodological way so I took an educated guess. In a 45-45-90 triangle, the largest side is √2 times the smallest side. The smallest side in our question is √2, so we know that the largest side (2 in our case) cannot be 2 (√2*√2) since this is not a 45-45-90 triangle. The largest side will have to be less than 2 and obviously more than √2 (the side opposite the smaller angle). We're only left with option C here. Is this approach correct?
Moderators:
Math Expert
109820 posts
Tuck School Moderator
853 posts