It is currently 18 Nov 2017, 11:05

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

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

What is the perimeter of an equilateral triangle inscribed

Author Message
TAGS:

Hide Tags

Intern
Joined: 16 Apr 2012
Posts: 8

Kudos [?]: 10 [1], given: 3

What is the perimeter of an equilateral triangle inscribed [#permalink]

Show Tags

09 Aug 2012, 13:06
1
KUDOS
3
This post was
BOOKMARKED
00:00

Difficulty:

35% (medium)

Question Stats:

68% (01:12) correct 32% (01:28) wrong based on 120 sessions

HideShow timer Statistics

What is the perimeter of an equilateral triangle inscribed in a circle of radius 4 ?

A. $$6\sqrt{2}$$
B. $$6\sqrt{3}$$
C. $$12\sqrt{2}$$
D. $$12\sqrt{3}$$
E. $$24$$

[Reveal] Spoiler: OA

Last edited by Bunuel on 09 Aug 2012, 15:05, edited 1 time in total.
Renamed the topic and edited the question.

Kudos [?]: 10 [1], given: 3

Magoosh GMAT Instructor
Joined: 28 Dec 2011
Posts: 4488

Kudos [?]: 8735 [1], given: 105

Re: What is the perimeter of an equilateral triangle inscribed [#permalink]

Show Tags

09 Aug 2012, 16:29
1
KUDOS
Expert's post
1
This post was
BOOKMARKED
arthuro69 wrote:
What is the perimeter of an equilateral triangle inscribed in a circle of radius 4 ?

A. $$6\sqrt{2}$$
B. $$6\sqrt{3}$$
C. $$12\sqrt{2}$$
D. $$12\sqrt{3}$$
E. $$24$$

Hi, there. I'm happy to help.

The full solution to the problem is in the attached pdf.

If the details of the 30-60-90 triangle are not familiar to you, I recommend brushing up with this post:
http://magoosh.com/gmat/2012/the-gmats- ... triangles/

Let me know if there are any further questions.

Mike
Attachments

_________________

Mike McGarry
Magoosh Test Prep

Education is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)

Kudos [?]: 8735 [1], given: 105

Intern
Joined: 03 Oct 2010
Posts: 4

Kudos [?]: [0], given: 2

Re: What is the perimeter of an equilateral triangle inscribed [#permalink]

Show Tags

04 Sep 2012, 03:29
The radius of circum circle of an equilateral triangle = a/sqrt(3). a is the side of triangle.
Here: a/sqrt(3) = 4
a = 4*sqrt(3).
perimeter 3a = 3*4*sqrt(3) = 12sqrt(3).

Kudos [?]: [0], given: 2

Math Expert
Joined: 02 Sep 2009
Posts: 42249

Kudos [?]: 132595 [0], given: 12326

Re: What is the perimeter of an equilateral triangle inscribed [#permalink]

Show Tags

04 Sep 2012, 03:32
arthuro69 wrote:
What is the perimeter of an equilateral triangle inscribed in a circle of radius 4 ?

A. $$6\sqrt{2}$$
B. $$6\sqrt{3}$$
C. $$12\sqrt{2}$$
D. $$12\sqrt{3}$$
E. $$24$$

All you need to know about triangles for the GMAT: math-triangles-87197.html

Hope it helps.
_________________

Kudos [?]: 132595 [0], given: 12326

Non-Human User
Joined: 09 Sep 2013
Posts: 15703

Kudos [?]: 281 [0], given: 0

Re: What is the perimeter of an equilateral triangle inscribed [#permalink]

Show Tags

06 Jul 2014, 05:49
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Kudos [?]: 281 [0], given: 0

Intern
Joined: 11 Nov 2013
Posts: 17

Kudos [?]: 11 [0], given: 17

GMAT 1: 680 Q50 V31
Re: What is the perimeter of an equilateral triangle inscribed [#permalink]

Show Tags

06 Jul 2014, 11:30
Let x be the side of triangle.

Using cosine rule:
(x/2)/R = cos 30
=> x = 2Rcos 30 = 4√3
=> Perimeter = 3X = 12√3

Kudos [?]: 11 [0], given: 17

Re: What is the perimeter of an equilateral triangle inscribed   [#permalink] 06 Jul 2014, 11:30
Display posts from previous: Sort by