It is currently 21 Feb 2018, 09:20

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Q. Find the perimeter of the isosceles triangle whose un

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Expert Post
1 KUDOS received
e-GMAT Representative
User avatar
S
Joined: 04 Jan 2015
Posts: 806
Q. Find the perimeter of the isosceles triangle whose un [#permalink]

Show Tags

New post 26 Apr 2017, 23:11
1
This post received
KUDOS
Expert's post
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

84% (01:20) correct 16% (02:47) wrong based on 47 sessions

HideShow timer Statistics

Q. Find the perimeter of the isosceles triangle whose unequal side is equal to 16 units and the area of the triangle is 48 sq.units

    A. 24 units
    B. 30 units
    C. 36 units
    D. 40 units
    E. 48 units


Thanks,
Saquib
Quant Expert
e-GMAT

Register for our Free Session on Number Properties (held every 3rd week) to solve exciting 700+ Level Questions in a classroom environment under the real-time guidance of our Experts :)

Image
[Reveal] Spoiler: OA

_________________












| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

Expert Post
e-GMAT Representative
User avatar
S
Joined: 04 Jan 2015
Posts: 806
Re: Q. Find the perimeter of the isosceles triangle whose un [#permalink]

Show Tags

New post 26 Apr 2017, 23:11
Reserving this space to post the official solution. :)
_________________












| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

Director
Director
User avatar
P
Joined: 05 Mar 2015
Posts: 962
Q. Find the perimeter of the isosceles triangle whose un [#permalink]

Show Tags

New post 27 Apr 2017, 00:17
EgmatQuantExpert wrote:
Q. Find the perimeter of the isosceles triangle whose unequal side is equal to 16 units and the area of the triangle is 48 sq.units

    A. 24 units
    B. 30 units
    C. 36 units
    D. 40 units
    E. 48 units


Thanks,
Saquib
Quant Expert
e-GMAT

Register for our Free Session on Number Properties (held every 3rd week) to solve exciting 700+ Level Questions in a classroom environment under the real-time guidance of our Experts :)

Image



Please refer attached below
Attachments

IMG_20170427_135653.jpg
IMG_20170427_135653.jpg [ 1.69 MiB | Viewed 1764 times ]

VP
VP
avatar
P
Joined: 22 May 2016
Posts: 1336
Premium Member CAT Tests
Q. Find the perimeter of the isosceles triangle whose un [#permalink]

Show Tags

New post 28 Apr 2017, 08:59
EgmatQuantExpert wrote:
Q. Find the perimeter of the isosceles triangle whose unequal side is equal to 16 units and the area of the triangle is 48 sq.units

    A. 24 units
    B. 30 units
    C. 36 units
    D. 40 units
    E. 48 units


Thanks,
Saquib
Quant Expert
e-GMAT


Great question. It tests a few key concepts simultaneously.

1. Properties of isosceles triangles: among others, if the median is drawn to the base (BM in diagram below):

a) the median is the altitude, which we need because we are given area and need to find perimeter, which will rely on property (1-c) below
b) the median/altitude is the perpendicular bisector of the base
c) it produces two congruent right triangles

Diagram is below

2. Draw a triangle ABC with base 16, other two equal sides labeled X. AB=BC

3. Draw the median, BM. Its height is derived from given area. Triangle area = 1/2*b*(height) => 48 = (1/2)(16)(BM) => 96 = 16 * BM => Height/BM = 6

4. Base AC is bisected perpendicularly, so we have two triangles with 90-degree angles and congruent sides, per c above. \(\frac{AC}{2}\) = \(\frac{16}{2}\)=8, 8=AM=CM. We now have two right triangles with values for legs: BM is 6, AM is 8 (CM also = 8).

5. Properties of right triangles: if you have two legs in the ratio 3x:4x, the hypotenuse will be 5x. (3-4-5 right triangle.) And per (a) and (c) above=>

6. Each equal side of the isosceles triangles is the hypotenuse of a 3-4-5 right triangle. You can either do the math with Pythagorean theorem or remember that 3-4-5 has all kinds of variations, including 6-8-10. We have BM is 6, AM is 8. So hypotenuse is 10.

Now you have two hypotenuse/equal sides of isosceles triangle with value X = 10. Find perimeter. 10 + 10 + 16 = 36.
Attachments

isosceles triangle.jpg
isosceles triangle.jpg [ 9.54 KiB | Viewed 1723 times ]


_________________

At the still point, there the dance is. -- T.S. Eliot
Formerly genxer123

Q. Find the perimeter of the isosceles triangle whose un   [#permalink] 28 Apr 2017, 08:59
Display posts from previous: Sort by

Q. Find the perimeter of the isosceles triangle whose un

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.