January 26, 2019 January 26, 2019 07:00 AM PST 09:00 AM PST Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions. January 27, 2019 January 27, 2019 07:00 AM PST 09:00 AM PST Attend this webinar to learn a structured approach to solve 700+ Number Properties question in less than 2 minutes.
Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 52431

Re: In triangle ABC, if BC = 3 and AC = 4, then what is the length of segm
[#permalink]
Show Tags
02 Jun 2015, 05:33
sheolokesh wrote: Hi Bunuel,
please explain me the correlation between 306090(1:sq(3):2), 454590(1:1:sq(2)) with pythagorean triplets(345, 72425). I am confused because if we have a 90deg triangle, and 2 sides 3,4 we can put other side as 5? If so then it becomes 306090 triangle right? then why we are not able to correlate 1:sq(3):2 with 3:4:5? because we need to commonly multiply the ratio, so if 1*3 then sq(3) must also multiply by 3 which is not equal to 4..
Because I had tried an another approach which gives a wrong ans... Need clarification.. If ABC is a right triangle with 3,4 then other side must be 5. So Angle BAC will be 30 deg. which makes Ang CAD as 60 and CDA as 30.. So we have 306090 triangle on ACD. If thats the case, then CD must be 4*sqrt(3) right? what's wrong in my approach?
Please help.. sheolokesh wrote: if we have a 90deg triangle, and 2 sides 3,4 we can put other side as 5 Yes. If 3 and 4 are legs of a right triangle, then hypotenuse is 5. sheolokesh wrote: If so then it becomes 306090 triangle right? No. The angles in 345 right triangle are NOT 30°60°90°. They are ~53°  ~37 °  90°.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Manager
Joined: 04 Jan 2014
Posts: 81

Re: In triangle ABC, if BC = 3 and AC = 4, then what is the length of segm
[#permalink]
Show Tags
02 Jun 2015, 06:00
So all triplets has 375390 degrees right? Its better not to confuse triplets with 306090 or 454590 then..



Math Expert
Joined: 02 Sep 2009
Posts: 52431

Re: In triangle ABC, if BC = 3 and AC = 4, then what is the length of segm
[#permalink]
Show Tags
02 Jun 2015, 06:07



Intern
Joined: 17 Sep 2016
Posts: 3

Re: In triangle ABC, if BC = 3 and AC = 4, then what is the length of segm
[#permalink]
Show Tags
11 Oct 2016, 08:37
Hey Could any one please tell me if my approach is correct! I used trigonometry!
Approach below: Consider triangle ABC cosθ = 3/5 (base/hyp)........(1) Consider triangle ABD cosθ = 5/(3+CD).........(2)
Equate (1) and (2)
3/5=5/(3+CD) 3CD+9= 25 ====> CD=16/3



CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2726
Location: India
GMAT: INSIGHT
WE: Education (Education)

Re: In triangle ABC, if BC = 3 and AC = 4, then what is the length of segm
[#permalink]
Show Tags
11 Oct 2016, 10:24
Quote: In triangle ABC, if BC = 3 and AC = 4, then what is the length of segment CD?
A. 3 B. 15/4 C. 5 D. 16/3 E. 20/3 As depicted in the figure, AB^2 = 3^2 + 4^2 = 5^2 i.e. AB = 5 NOW TRIANGLE ABC AND TRIANGLE ACD ARE SIMILAR TRIANGLE So the ratio of their corresponding sides will be equal AC/BC = CD/AC 4/3 = CD/4 i.e. CD = 16/3 Answer: option D
Attachments
File comment: www.GMATinsight.com
Sol1.jpg [ 25.87 KiB  Viewed 9040 times ]
_________________
Prosper!!! GMATinsight Bhoopendra Singh and Dr.Sushma Jha email: info@GMATinsight.com I Call us : +919999687183 / 9891333772 Online OneonOne Skype based classes and Classroom Coaching in South and West Delhi http://www.GMATinsight.com/testimonials.html
ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION



Intern
Joined: 22 Sep 2018
Posts: 1

Re: In triangle ABC, if BC = 3 and AC = 4, then what is the length of segm
[#permalink]
Show Tags
30 Sep 2018, 01:24
How the angle BAC is equal to angle ADC



CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2726
Location: India
GMAT: INSIGHT
WE: Education (Education)

Re: In triangle ABC, if BC = 3 and AC = 4, then what is the length of segm
[#permalink]
Show Tags
30 Sep 2018, 04:38
sudhanshutiwari wrote: How the angle BAC is equal to angle ADC sudhanshutiwariTake bigger triangle ABD and mark Angles as 90x  (90x) Now look at triangle ACD, one of the angle you can already see marked is (90x) one angle is 90 so third angle becomes x (if you subtract other two angles from 180) Similarly, look at triangle ABC, one of the angle you can already see marked is x one angle is 90 so third angle becomes 90x (if you subtract other two angles from 180) This is how, we figure out that angle BAC is equal to angle ADC I hope this helps
_________________
Prosper!!! GMATinsight Bhoopendra Singh and Dr.Sushma Jha email: info@GMATinsight.com I Call us : +919999687183 / 9891333772 Online OneonOne Skype based classes and Classroom Coaching in South and West Delhi http://www.GMATinsight.com/testimonials.html
ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION




Re: In triangle ABC, if BC = 3 and AC = 4, then what is the length of segm &nbs
[#permalink]
30 Sep 2018, 04:38



Go to page
Previous
1 2
[ 27 posts ]



