BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

Triangles

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 27
Joined: Thu Jan 29, 2009 9:57 am
Thanked: 1 times
by masuarezdl » Wed Jul 15, 2009 11:06 am
In isoceles triangle RST what is the measure of angle R?

(1) The measure of angle T is 100deg.
(2) The measure of angle S is 40 deg.

Whats the logic behind this? I though both worked out alone sufficiently...
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
Master | Next Rank: 500 Posts
Posts: 316
Joined: Mon Sep 22, 2008 12:04 amFollowed by: 1 member
Thanked: 36 times

Re: Triangles

by Morgoth » Wed Jul 15, 2009 11:14 am
masuarezdl wrote:In isoceles triangle RST what is the measure of angle R?

(1) The measure of angle T is 100deg.
(2) The measure of angle S is 40 deg.

Whats the logic behind this? I though both worked out alone sufficiently...
Statement I

if angle T is 100 the other 2 angles are equal since the triangle is an isosceles triangle. Also angle T cannot be equal to another angle because then the sum of the 2 angles will be greater than 180

T + R+S = 180
100+2R = 180 [since R=S]
R = 40

Sufficient.

Statement II
Angle S = 40

angle S could be equal to angle T or angle R we don't know which of the 2 angles are equal.

Insufficient.

Hence A.
Hope this helps.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Junior | Next Rank: 30 Posts
Posts: 27
Joined: Thu Jan 29, 2009 9:57 am
Thanked: 1 times

Re: Triangles

by masuarezdl » Wed Jul 15, 2009 11:42 am
Morgoth wrote:
masuarezdl wrote:In isoceles triangle RST what is the measure of angle R?

(1) The measure of angle T is 100deg.
(2) The measure of angle S is 40 deg.

Whats the logic behind this? I though both worked out alone sufficiently...
Statement I

if angle T is 100 the other 2 angles are equal since the triangle is an isosceles triangle. Also angle T cannot be equal to another angle because then the sum of the 2 angles will be greater than 180

T + R+S = 180
100+2R = 180 [since R=S]
R = 40

Sufficient.

Statement II
Angle S = 40

angle S could be equal to angle T or angle R we don't know which of the 2 angles are equal.

Insufficient.

Hence A.
Hope this helps.
I cannot believe i missed that... thanks!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1