Last visit was: 23 Apr 2026, 15:45 It is currently 23 Apr 2026, 15:45
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
Sub 505 (Easy)|   Coordinate Geometry|                           
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,785
Own Kudos:
Given Kudos: 105,853
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,785
Kudos: 810,862
 [37]
1
Kudos
Add Kudos
36
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,785
Own Kudos:
Given Kudos: 105,853
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,785
Kudos: 810,862
 [16]
8
Kudos
Add Kudos
8
Bookmarks
Bookmark this Post
General Discussion
User avatar
blueseas
User avatar
Current Student
Joined: 14 Dec 2012
Last visit: 15 Jan 2019
Posts: 572
Own Kudos:
4,535
 [1]
Given Kudos: 197
Location: India
Concentration: General Management, Operations
GMAT 1: 700 Q50 V34
GPA: 3.6
GMAT 1: 700 Q50 V34
Posts: 572
Kudos: 4,535
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
onedayill
Joined: 25 Feb 2010
Last visit: 08 Mar 2017
Posts: 207
Own Kudos:
341
 [1]
Given Kudos: 10
Posts: 207
Kudos: 341
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
IMO - B

base = c-1
y = b
therefore area =((c-1)b)/2
User avatar
Abdul29
Joined: 11 Jan 2014
Last visit: 20 Nov 2024
Posts: 78
Own Kudos:
Given Kudos: 11
Concentration: Finance, Statistics
GMAT Date: 03-04-2014
GPA: 3.77
WE:Analyst (Retail Banking)
Posts: 78
Kudos: 421
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Area of a triangle is given by: (Base * Height)/2

Base is measured by length on the x-axis, thus, c-1. Height is measured by the vertical axis y, so, coordinate b from point S.
Hence, b(c-1)/2, which is (B).
User avatar
rhine29388
Joined: 24 Nov 2015
Last visit: 21 Oct 2019
Posts: 386
Own Kudos:
146
 [1]
Given Kudos: 231
Location: United States (LA)
Products:
Posts: 386
Kudos: 146
 [1]
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Area of triangle = \(\frac{1}{2}\) * base * height
Base is (c-1) for given triangle
Height is b for given triangle
Area = \(\frac{1}{2}\) * b * (c-1)

Correct Answer - B
avatar
hanvd1990
Joined: 09 Oct 2017
Last visit: 23 Oct 2022
Posts: 10
Own Kudos:
Given Kudos: 72
Location: Viet Nam
GMAT 1: 530 Q35 V28
GPA: 3.1
GMAT 1: 530 Q35 V28
Posts: 10
Kudos: 5
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel

In the rectangular coordinate system above, the area of triangle RST is

(A) bc/2
(B) b(c-1)/2
(C) c(b-1)/2
(D) a(c-1)/2
(E) c(a-1)/2

The area of a triangle is 1/2*(base)(height):

(base) = c - 1 (the difference between the x-coordinates of points T and R).

(height) = b (the "height", the y-coordinate, of point S).

Therefore, the area is 1/2*(base)(height) = 1/2*(c - 1)b.

Answer: B.

Hi Bunuel, may I ask how you know this triangle is a right triangle? The picture does not indicate that it is a right triangle and we cannot figure out from the coordinates of the vertices either? Please correct me if I am wrong. Thank you!
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,785
Own Kudos:
810,862
 [1]
Given Kudos: 105,853
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,785
Kudos: 810,862
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
hanvd1990
Bunuel

In the rectangular coordinate system above, the area of triangle RST is

(A) bc/2
(B) b(c-1)/2
(C) c(b-1)/2
(D) a(c-1)/2
(E) c(a-1)/2

The area of a triangle is 1/2*(base)(height):

(base) = c - 1 (the difference between the x-coordinates of points T and R).

(height) = b (the "height", the y-coordinate, of point S).

Therefore, the area is 1/2*(base)(height) = 1/2*(c - 1)b.

Answer: B.

Hi Bunuel, may I ask how you know this triangle is a right triangle? The picture does not indicate that it is a right triangle and we cannot figure out from the coordinates of the vertices either? Please correct me if I am wrong. Thank you!

Where did I assume that the triangle is right?
avatar
hanvd1990
Joined: 09 Oct 2017
Last visit: 23 Oct 2022
Posts: 10
Own Kudos:
Given Kudos: 72
Location: Viet Nam
GMAT 1: 530 Q35 V28
GPA: 3.1
GMAT 1: 530 Q35 V28
Posts: 10
Kudos: 5
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
hanvd1990
Bunuel

In the rectangular coordinate system above, the area of triangle RST is

(A) bc/2
(B) b(c-1)/2
(C) c(b-1)/2
(D) a(c-1)/2
(E) c(a-1)/2

The area of a triangle is 1/2*(base)(height):

(base) = c - 1 (the difference between the x-coordinates of points T and R).

(height) = b (the "height", the y-coordinate, of point S).

Therefore, the area is 1/2*(base)(height) = 1/2*(c - 1)b.

Answer: B.

Hi Bunuel, may I ask how you know this triangle is a right triangle? The picture does not indicate that it is a right triangle and we cannot figure out from the coordinates of the vertices either? Please correct me if I am wrong. Thank you!

Where did I assume that the triangle is right?
Thank you Bunuel, when I read your explanation again, I understand it now.
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,962
Own Kudos:
Posts: 38,962
Kudos: 1,117
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Math Expert
109785 posts
Tuck School Moderator
853 posts