• Free Practice Test & Review
How would you score if you took the GMAT

Available with Beat the GMAT members only code

• Award-winning private GMAT tutoring
Register now and save up to $200 Available with Beat the GMAT members only code • Get 300+ Practice Questions 25 Video lessons and 6 Webinars for FREE Available with Beat the GMAT members only code • 5-Day Free Trial 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • 5 Day FREE Trial Study Smarter, Not Harder Available with Beat the GMAT members only code • Free Veritas GMAT Class Experience Lesson 1 Live Free Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

Available with Beat the GMAT members only code

• 1 Hour Free
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Free Trial & Practice Exam
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

## Great circles question

This topic has 2 member replies
mihai9 Junior | Next Rank: 30 Posts
Joined
08 Nov 2017
Posted:
19 messages

#### Great circles question

Fri Dec 22, 2017 10:29 am
There are three points O, P, Q, O is the center of the circle, P and Q are two points on the circle, and âˆ POQ is 45 Â°, then it seems that the area of a triangle is 12, Find the area of a circle ?

thucanh711 Newbie | Next Rank: 10 Posts
Joined
23 Dec 2017
Posted:
3 messages
Sun Jan 07, 2018 3:15 am
Hi there,

As O is the center of the circle and P, Q are on the circle => OP = OQ = r (the radius of the circle)

The area of the triangle can be calculated by: S = 1/2 sin($$\angle$$ POQ) OP. OQ = 1/2 . $$\frac{\sqrt{2}}{2}$$ . OP . OQ

We have S = 12 => the value of OP.OQ

OP.OQ = r. r = $$r^2$$

The area of the circle: S' = $$\pi.r^2$$

DrMaths Senior | Next Rank: 100 Posts
Joined
15 Jan 2018
Posted:
82 messages
Thu Feb 01, 2018 8:22 am
8 of these triangles will make an octagon, whose area is 2âˆš2r^2
So 2âˆš2r^2 = 8 * 12
âˆš2r^2 = 48
r^2 = 24âˆš2

Area of circle = pi * r^2 = pi * 24âˆš2

### Top First Responders*

1 GMATGuruNY 72 first replies
2 Rich.C@EMPOWERgma... 45 first replies
3 Brent@GMATPrepNow 43 first replies
4 Jay@ManhattanReview 27 first replies
5 ErikaPrepScholar 9 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

### Most Active Experts

1 GMATGuruNY

The Princeton Review Teacher

133 posts
2 Rich.C@EMPOWERgma...

EMPOWERgmat

118 posts
3 Jeff@TargetTestPrep

Target Test Prep

105 posts
4 Max@Math Revolution

Math Revolution

93 posts
5 Scott@TargetTestPrep

Target Test Prep

92 posts
See More Top Beat The GMAT Experts