GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 17 Oct 2019, 08:32

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

In triangle ABC, we have AC = BC = 7 and AB = 2. Suppose that D is a p

Author Message
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 58401
In triangle ABC, we have AC = BC = 7 and AB = 2. Suppose that D is a p  [#permalink]

Show Tags

24 Mar 2019, 23:03
00:00

Difficulty:

45% (medium)

Question Stats:

75% (04:04) correct 25% (02:07) wrong based on 19 sessions

HideShow timer Statistics

In triangle ABC, we have AC = BC = 7 and AB = 2. Suppose that D is a point on line AB such that B lies between A and D and CD = 8. What is BD ?

(A) 3

(B) $$2\sqrt{3}$$

(C) 4

(D) 5

(E) $$4\sqrt{2}$$

_________________
Intern
Joined: 27 Sep 2018
Posts: 37
Re: In triangle ABC, we have AC = BC = 7 and AB = 2. Suppose that D is a p  [#permalink]

Show Tags

24 Mar 2019, 23:29
Triangle CAB is isosceles triangle with base AB=2 and AC=BC=7

Dropping a perpendicular from C on AB at E will bisect AB I.e EB=1

Also triangle CEB will be right angled triangle, with hypotenuse CB=7, base EB=1, and perpendicular can be calculated using Pythagoras

Perpendicular= rt(CB^2-EB^2)=rt48

Also triangle CED is right angled triangle where perpendicular CE=rt48, hypotenuse, CD=8 and base ED=x

Using Pythagoras find ED
ED=rt(8^2-48)=rt16=4
BD=ED-EB=4-1=3

Posted from my mobile device
Re: In triangle ABC, we have AC = BC = 7 and AB = 2. Suppose that D is a p   [#permalink] 24 Mar 2019, 23:29
Display posts from previous: Sort by