Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 49953

In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
22 Sep 2015, 03:15
Question Stats:
67% (00:52) correct 33% (00:56) wrong based on 186 sessions
HideShow timer Statistics



Intern
Joined: 02 Jan 2014
Posts: 39

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
22 Sep 2015, 04:49
Bunuel wrote: In isosceles triangle DEF, what is the measure of angle E?
(1) Angle D measures 42 degrees (2) Angle F measures 96 degrees
Kudos for a correct solution. Answer is B. The sum of the angles of a Triangle is 180, if F is 96 that means , another angle cannot be the same as 96 because 96+96 exceeds 180. However, we can deduce that remaining two angles are equal. so (18096)/2 will be the value of angle E.



Manager
Joined: 17 Jun 2015
Posts: 220
GMAT 1: 540 Q39 V26 GMAT 2: 680 Q46 V37

In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
22 Sep 2015, 05:25
Statement A<D = 42 degrees. The remaining needs to be 180  42 = 138 degrees. There could be two cases. In first case, <D is the angle that has an equal counterpart. In that case, the two angles combine to give 42 + 42 = 84 degrees. The remaining angle is 96 degrees. But which angle measures 96 degrees  E or F. Hence, this statement is insufficient.Statement B<F = 96 degrees. This cannot be one of the two equal angles in the isosceles triangle as it violates the rule that sum of three angles of a triangle is equal to 180 degrees. Hence the remaining two angles contribute to the 180  96 = 84 degrees. And the two equal angles are 42 degrees each. In any case, <E is equal to 42 degrees. Hence B is sufficient. Rules used: 1. An isosceles triangle has two equal sides and two equal angles 2. The sum of three angles of any triangle (across the Newtonian realm of existence) is 180 degree
_________________
Fais de ta vie un rêve et d'un rêve une réalité



Manager
Joined: 29 Jul 2015
Posts: 159

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
22 Sep 2015, 11:02
Bunuel wrote: In isosceles triangle DEF, what is the measure of angle E?
(1) Angle D measures 42 degrees (2) Angle F measures 96 degrees
Kudos for a correct solution. Statement 1: It doesn't specify which angles are equal. The angles can be 42,42,96 or 42,69,69 INSUFFICIENT Statement 2: Angle F is 96 degrees. It is an obtuse angle. Sine there cannot be 2 obtuse angles in the triangle, 96 cannot be one of the equal angles. So, the other two angles are equal with each angle measuring 42 degrees each. SUFFICIENT Answer:B



Intern
Joined: 14 Mar 2015
Posts: 33

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
22 Sep 2015, 12:49
Bunuel wrote: In isosceles triangle DEF, what is the measure of angle E?
(1) Angle D measures 42 degrees (2) Angle F measures 96 degrees
Kudos for a correct solution. In Isosceles triangle DEF, we have 3 configurations a) DE = EF (angle D = angle F) b) DE = DF (angle E = angle F) c) EF= DF (angle E = angle D) Evaluate1) Info about only angle D is given. We don't know which of the above configuration is there for this triangle DEF. So this is INSUFFICIENT. 2) Angle F = 96. Sum of remaining two angles will be 180  96 = 84*. Now, we can't have two angles measuring 96 degrees. So the rest two angles (angle D and angle E) have to be equal; angle D = angle E = 84/2 = 42 degrees. So this is SUFFICIENT. Correct Answer B.
_________________
It ain’t about how hard you hit. It’s about how hard you can get hit and keep moving forward; how much you can take and keep moving forward. That’s how winning is done!



Intern
Joined: 19 Dec 2014
Posts: 35

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
22 Sep 2015, 15:11
In isosceles triangle DEF, what is the measure of angle E?
(1) Angle D measures 42 degrees (2) Angle F measures 96 degrees
Statement 1 : D = 42 so, E + F = 180  42 = 138
since DEF is isosceles E and F can be equal and measure = 69 if E = F ; D = 42, E=F = 69 if D is equal to one anther angle then the third angle = 96.
two possibilities. therefore Insufficient
Statement 2 : F = 96 so, D + E = 180  96 = 84
since DEF is isosceles D and E can be equal and measure = 42 if F is equal to another angle then the total = 96 + 96 = 192
But sum of angles of triangle = 180.
so D = 42 Sufficient
Answer = B



Intern
Joined: 13 Nov 2014
Posts: 46
GMAT 1: 590 Q42 V29 GMAT 2: 630 Q47 V29

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
22 Sep 2015, 20:24
IMO B, with just 1st option, there are two possibilities with 2nd option there is only 1 choice for other angles
_________________
 Consider Cudos if you like this post. 



Manager
Joined: 12 Mar 2015
Posts: 93
Concentration: Leadership, Finance
GPA: 3.9
WE: Information Technology (Computer Software)

In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
23 Sep 2015, 08:30
Bunuel wrote: In isosceles triangle DEF, what is the measure of angle E?
(1) Angle D measures 42 degrees (2) Angle F measures 96 degrees
Kudos for a correct solution. IMO: B Clearly A is not sufficient. 2(96) > 180. this condition is not possible. Therefor 96 can be one of the angles. Now other two angles can be found out. So B is sufficient



Intern
Joined: 14 Mar 2015
Posts: 33

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
28 Sep 2015, 03:25
@Bunnel vivekgautam1 wrote: Bunuel wrote: In isosceles triangle DEF, what is the measure of angle E?
(1) Angle D measures 42 degrees (2) Angle F measures 96 degrees
Kudos for a correct solution. In Isosceles triangle DEF, we have 3 configurations a) DE = EF (angle D = angle F) b) DE = DF (angle E = angle F) c) EF= DF (angle E = angle D) Evaluate1) Info about only angle D is given. We don't know which of the above configuration is there for this triangle DEF. So this is INSUFFICIENT. 2) Angle F = 96. Sum of remaining two angles will be 180  96 = 84*. Now, we can't have two angles measuring 96 degrees. So the rest two angles (angle D and angle E) have to be equal; angle D = angle E = 84/2 = 42 degrees. So this is SUFFICIENT. Correct Answer B. Hi Bunnel Kudos for this please
_________________
It ain’t about how hard you hit. It’s about how hard you can get hit and keep moving forward; how much you can take and keep moving forward. That’s how winning is done!



Current Student
Joined: 20 Mar 2014
Posts: 2633
Concentration: Finance, Strategy
GPA: 3.7
WE: Engineering (Aerospace and Defense)

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
28 Sep 2015, 03:50
vivekgautam1 wrote: @Bunnel vivekgautam1 wrote: Bunuel wrote: In isosceles triangle DEF, what is the measure of angle E?
(1) Angle D measures 42 degrees (2) Angle F measures 96 degrees
Kudos for a correct solution. In Isosceles triangle DEF, we have 3 configurations a) DE = EF (angle D = angle F) b) DE = DF (angle E = angle F) c) EF= DF (angle E = angle D) Evaluate1) Info about only angle D is given. We don't know which of the above configuration is there for this triangle DEF. So this is INSUFFICIENT. 2) Angle F = 96. Sum of remaining two angles will be 180  96 = 84*. Now, we can't have two angles measuring 96 degrees. So the rest two angles (angle D and angle E) have to be equal; angle D = angle E = 84/2 = 42 degrees. So this is SUFFICIENT. Correct Answer B. Hi Bunnel Kudos for this please Do not ask for Kudos. If your post deserves one, Bunuel will give you 1 kudos.



Manager
Joined: 23 Aug 2012
Posts: 73
Concentration: Technology

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
29 Sep 2015, 11:39
I believe the answer is B. Please see below for explanation.
0) From the question we get that triangle DEF is isosceles meaning that two sides are equal and also that two angles are equal.
(1) From statement 1 we get that Angle D measures 42 degrees
If angle D measures 42 that could mean that angle E could be 42 and angle F could be 180  2*42 = 96
or
If angle D measures 42 that means that angle F could be 42 and angle E could be 180  2*42 = 96
(2) Angle F measures 96 degrees
If angle F measures 96 degrees it means that F has to be the biggest angle, because 96+96 = 192 and that is bigger than 180. Another away to put it would be that there can't be another angle equal to 96 (Isosceles remember). With this in mind and if F is the biggest angle then the remaining angles must be (18096)/2
Answer B



Math Expert
Joined: 02 Sep 2009
Posts: 49953

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
05 Oct 2015, 03:02



Intern
Joined: 02 Jan 2014
Posts: 39

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
01 Nov 2015, 23:44
Has everyone got their Kudos?



NonHuman User
Joined: 09 Sep 2013
Posts: 8427

Re: In isosceles triangle DEF, what is the measure of angle E?
[#permalink]
Show Tags
23 Sep 2018, 07:46
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.
_________________
GMAT Books  GMAT Club Tests  Best Prices on GMAT Courses  GMAT Mobile App  Math Resources  Verbal Resources




Re: In isosceles triangle DEF, what is the measure of angle E? &nbs
[#permalink]
23 Sep 2018, 07:46






