Area of Triangle

This topic has expert replies
User avatar
Master | Next Rank: 500 Posts
Posts: 184
Joined: Sun Aug 19, 2012 10:04 pm
Thanked: 10 times
Followed by:2 members

Area of Triangle

by Mission2012 » Thu Aug 15, 2013 6:43 pm
What is the greatest possible area of a triangular region with one vertex at the center of a circle of radius 1 and the other two vertices on the circle?

(A) 3√4

(B) 12

(C) π4

(D) 1

(E)√2
If you find my post useful -> please click on "Thanks"
Source: — Problem Solving |

User avatar
Master | Next Rank: 500 Posts
Posts: 283
Joined: Sun Jun 23, 2013 11:56 pm
Location: Bangalore, India
Thanked: 97 times
Followed by:26 members
GMAT Score:750

by ganeshrkamath » Thu Aug 15, 2013 8:03 pm
Mission2012 wrote:What is the greatest possible area of a triangular region with one vertex at the center of a circle of radius 1 and the other two vertices on the circle?

(A) 3√4

(B) 12

(C) π4

(D) 1

(E)√2

Area = 1/2 * base * height
Maximize the product:
base = 1
height = 1
Maximum area = 1/2 * 1 * 1
= 1/2
Every job is a self-portrait of the person who did it. Autograph your work with excellence.

Kelley School of Business (Class of 2016)
GMAT Score: 750 V40 Q51 AWA 5 IR 8
https://www.beatthegmat.com/first-attemp ... tml#688494

User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Thu Aug 15, 2013 8:18 pm
Mission2012 wrote:What is the greatest possible area of a triangular region with one vertex at the center of a circle of radius 1 and the other two vertices on the circle?

(A) √3/4

(B) 12

(C) 4Ï€

(D) 1

(E)√2
Image

The drawings above show 3 different versions of the triangle.

Leftmost drawing: b=1, h=1.
Middle drawing: b=1, h<1.
Rightmost drawing: b=1, h<1.

Notice that in each triangle b=1, but only in the leftmost triangle does h=1. In the other two triangles, h<1, resulting in a smaller area. The drawings above illustrate the following rule:

Given two sides of a triangle, the greatest area will be achieved when a right angle is placed between them (as in the leftmost triangle).

Thus, the greatest possible area = 1/2 * 1 * 1 = 1/2.

The correct answer is B.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3