Last visit was: 30 Apr 2026, 18:50 It is currently 30 Apr 2026, 18:50
Home
Messages
Tests
Schools
Events
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
605-655 (Medium)|   Geometry|      
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 30 Apr 2026
Posts: 110,017
Own Kudos:
812,164
 [10]
Given Kudos: 105,962
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 110,017
Kudos: 812,164
 [10]
An equilateral triangle is inscribed in a circle, as shown above. What Updated on: 11 Jul 2019, 05:43
Originally posted by Bunuel on 14 May 2017, 12:06.
Last edited by Sajjad1994 on 11 Jul 2019, 05:43, edited 1 time in total.
Added Source
Kudos
Add Kudos
10
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

45% (medium)

Question Stats:

59% (01:17) correct 41% (01:35) wrong based on 234 sessions

History

Date
Time
Result
Not Attempted Yet

An equilateral triangle is inscribed in a circle, as shown above. What is the area of the triangle?

(1) The radius of the circle is 2.
(2) The ratio of the radius of the circle to a side of the triangle is \(1: \sqrt{3}\)

Source: Nova GMAT
Difficulty Level: 700
Show Spoiler
Attachment:
2017-05-14_2305.png
2017-05-14_2305.png [ 7.85 KiB | Viewed 21649 times ]
ShowHide Answer
Official Answer
A
Most Helpful Reply
User avatar
BillyZ
User avatar
Current Student
Joined: 14 Nov 2016
Last visit: 24 Jan 2026
Posts: 1,135
Own Kudos:
22,622
 [8]
Given Kudos: 926
Location: Malaysia
Concentration: General Management, Strategy
Schools: Sloan '23 (D) Tuck '23 (D) Darden '23 (D) Ross '23 (D) Kellogg '23 (D) Wharton '23 (D) Booth '23 (D) Fuqua '24 (A) Harvard '24 (D) Stanford '24 (D)
GMAT 1: 750 Q51 V40 (Online)
GPA: 3.53
Products:
My Reviews
Schools: Sloan '23 (D) Tuck '23 (D) Darden '23 (D) Ross '23 (D) Kellogg '23 (D) Wharton '23 (D) Booth '23 (D) Fuqua '24 (A) Harvard '24 (D) Stanford '24 (D)
GMAT 1: 750 Q51 V40 (Online)
Posts: 1,135
Kudos: 22,622
 [8]
An equilateral triangle is inscribed in a circle, as shown above. What 17 May 2017, 03:43
2
Kudos
Add Kudos
6
Bookmarks
Bookmark this Post
ziyuen
An equilateral triangle is inscribed in a circle, as shown above. What is the area of the triangle?

(1) The radius of the circle is 2.
(2) The ratio of the radius of the circle to a side of the triangle is \(1: \sqrt{3}\)

\(Area(triangle)=a^2*\frac{√3}{{4}}\)

\(Radius = a* \frac{√3}{{3}}=2\)

Answer : A
Show more

laxpro2001
Can you please explain your triangle area formula. I get the area as being \(Area(triangle)=a^2*\frac{√3}{{2}}\)

Also can you please explain the your formula for radius? I tried calculating that but also got something different.

Thanks!
Show more

laxpro2001, Do refer the attachment.

https://gmatclub.com/forum/math-triangles-87197.html
Attachments

triangle.jpg
triangle.jpg [ 79.22 KiB | Viewed 17671 times ]

General Discussion
User avatar
gmatexam439
User avatar
Moderator
Joined: 28 Mar 2017
Last visit: 18 Oct 2024
Posts: 1,054
Own Kudos:
2,196
 [1]
Given Kudos: 200
Location: India
Concentration: Finance, Technology
Schools: McDonough '21 (A$) Jones '21 (A$) Kelley '23 (A)
GMAT 1: 730 Q49 V41
GPA: 4
Products:
My Reviews
Schools: McDonough '21 (A$) Jones '21 (A$) Kelley '23 (A)
GMAT 1: 730 Q49 V41
Posts: 1,054
Kudos: 2,196
 [1]
An equilateral triangle is inscribed in a circle, as shown above. What 14 May 2017, 12:49
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Bunuel

An equilateral triangle is inscribed in a circle, as shown above. What is the area of the triangle?

(1) The radius of the circle is 2.
(2) The ratio of the radius of the circle to a side of the triangle is \(1: \sqrt{3}\)


Show Spoiler
Attachment:
The attachment 2017-05-14_2305.png is no longer available
Show more

A

1. as per the attached figure, we can find s by using the following formulae:
s=2r * sin(theta/2)
sufficient

2. ratio neither tells us the side nor the radius.
insufficient
Attachments

Circle.png
Circle.png [ 5.76 KiB | Viewed 17688 times ]

User avatar
BillyZ
User avatar
Current Student
Joined: 14 Nov 2016
Last visit: 24 Jan 2026
Posts: 1,135
Own Kudos:
22,622
 [3]
Given Kudos: 926
Location: Malaysia
Concentration: General Management, Strategy
Schools: Sloan '23 (D) Tuck '23 (D) Darden '23 (D) Ross '23 (D) Kellogg '23 (D) Wharton '23 (D) Booth '23 (D) Fuqua '24 (A) Harvard '24 (D) Stanford '24 (D)
GMAT 1: 750 Q51 V40 (Online)
GPA: 3.53
Products:
My Reviews
Schools: Sloan '23 (D) Tuck '23 (D) Darden '23 (D) Ross '23 (D) Kellogg '23 (D) Wharton '23 (D) Booth '23 (D) Fuqua '24 (A) Harvard '24 (D) Stanford '24 (D)
GMAT 1: 750 Q51 V40 (Online)
Posts: 1,135
Kudos: 22,622
 [3]
An equilateral triangle is inscribed in a circle, as shown above. What 15 May 2017, 20:11
2
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Bunuel

An equilateral triangle is inscribed in a circle, as shown above. What is the area of the triangle?

(1) The radius of the circle is 2.
(2) The ratio of the radius of the circle to a side of the triangle is \(1: \sqrt{3}\)


Show Spoiler
Attachment:
2017-05-14_2305.png
Show more

\(Area(triangle)=a^2*\frac{√3}{{4}}\)

\(Radius = a* \frac{√3}{{3}}=2\)

Answer : A
avatar
laxpro2001
avatar
Joined: 30 Mar 2017
Last visit: 28 Sep 2018
Posts: 29
Own Kudos:
28
Given Kudos: 47
Location: United States (FL)
Posts: 29
Kudos: 28
An equilateral triangle is inscribed in a circle, as shown above. What 17 May 2017, 03:38
Kudos
Add Kudos
Bookmarks
Bookmark this Post
An equilateral triangle is inscribed in a circle, as shown above. What is the area of the triangle?

(1) The radius of the circle is 2.
(2) The ratio of the radius of the circle to a side of the triangle is \(1: \sqrt{3}\)


Show Spoiler
Attachment:
2017-05-14_2305.png
[/quote]

\(Area(triangle)=a^2*\frac{√3}{{4}}\)

\(Radius = a* \frac{√3}{{3}}=2\)

Answer : A[/quote]

Can you please explain your triangle area formula. I get the area as being \(Area(triangle)=a^2*\frac{√3}{{2}}\)

Also can you please explain the your formula for radius? I tried calculating that but also got something different.

Thanks!
avatar
laxpro2001
avatar
Joined: 30 Mar 2017
Last visit: 28 Sep 2018
Posts: 29
Own Kudos:
28
Given Kudos: 47
Location: United States (FL)
Posts: 29
Kudos: 28
An equilateral triangle is inscribed in a circle, as shown above. What 18 May 2017, 02:47
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Thank you, ziyuen
User avatar
QuantMadeEasy
User avatar
Joined: 28 Feb 2014
Last visit: 01 Mar 2026
Posts: 502
Own Kudos:
802
Given Kudos: 78
Location: India
Concentration: General Management, International Business
GPA: 3.97
WE:Engineering (Education)
Posts: 502
Kudos: 802
An equilateral triangle is inscribed in a circle, as shown above. What 28 Dec 2019, 22:50
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel

An equilateral triangle is inscribed in a circle, as shown above. What is the area of the triangle?

(1) The radius of the circle is 2.
(2) The ratio of the radius of the circle to a side of the triangle is \(1: \sqrt{3}\)

Source: Nova GMAT
Difficulty Level: 700
Show Spoiler
Attachment:
2017-05-14_2305.png
Show more
Side length of the triangle is required

(1) 30-60-90 triangle can be formed by dropping a perpendicular from center of the circle on the side of the triangle. Side length of the equilateral triangle can now be calculated as radius is known. Sufficient

(2) ratio of radius of circle to side length of the triangle is not sufficient to find side length as the ratio is already known from 30-60-90 triangle. Insufficient

Therefore, A is correct.
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 39,011
Own Kudos:
1,122
Posts: 39,011
Kudos: 1,122
An equilateral triangle is inscribed in a circle, as shown above. What 18 Mar 2023, 10:28
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Bunuel
Math Expert
110017 posts
kingbucky
498 posts
Gmat860sanskar
212 posts