In the figure above, the area of the shaded region is

This topic has expert replies
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3008
Joined: Mon Aug 22, 2016 6:19 am
Location: Grand Central / New York
Thanked: 470 times
Followed by:34 members

by Jay@ManhattanReview » Mon Dec 23, 2019 3:42 am
BTGmoderatorDC wrote:Image


In the figure above, the area of the shaded region is

A. \(8\sqrt{2}\)

B. \(4\sqrt{3}\)

C. \(4\sqrt{2}\)

D. \(8\sqrt{3} - 1)\)

E. \(8\sqrt{2} - 1)\)


OA D

Source: Official Guide
Note that the two sides of the non-shades quadrilateral are 4 and each angle is 90º, thus, it is a square. Thus, the length of the diagonal = 4√2.

This makes an equilateral triangle with a side 4√2. The area of the equilateral triangle = √3/4*side^2 = √3/4*(4√2)^ = 8√3

Area of the shaded region = Area of the equilateral triangle - Area of half-square = 8√3 - (4*4)/2 = 8√3 - 8 = 8(√3 - 1)

The correct answer: [spoiler][/spoiler]

Hope this helps!

-Jay
_________________
Manhattan Review GRE Prep

Locations: GMAT Classes San Diego | GRE Prep Course Boston | GRE Prep Chicago | TOEFL Prep Classes NYC | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.