Last visit was: 05 Nov 2024, 18:45 It is currently 05 Nov 2024, 18:45

Close

GRE Prep 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 GRE 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
Verbal Expert
Joined: 18 Apr 2015
Posts: 29894
Own Kudos [?]: 36130 [6]
Given Kudos: 25919
Send PM
Intern
Intern
Joined: 11 Aug 2020
Posts: 45
Own Kudos [?]: 76 [3]
Given Kudos: 17
Send PM
avatar
Intern
Intern
Joined: 23 Feb 2020
Posts: 14
Own Kudos [?]: 9 [1]
Given Kudos: 0
Send PM
Intern
Intern
Joined: 11 Aug 2020
Posts: 45
Own Kudos [?]: 76 [1]
Given Kudos: 17
Send PM
Re: The area of the circle above, with center C, is [#permalink]
1
fabiha22 wrote:
cote wrote:
The area of any triangle with a x° angle in the domain of 90° < x < 180°, is less than the area of a triangle with x=90°. Having said that, we can calculate the area of a 90 degress triangle:

Area of the circle
\(Á_{circle} = \pi*r = 36\pi\)
\(r = 6\)
but, we know that the area of a triangle is given by:
\(Á_{triangle} = \frac{b*h}{2}\)
and, because we have a isoseles, the area is:
\(Á_{triangle} = \frac{r*r}{2} = \frac{6*6}{2}\)
\(Á_{triangle} = 18\)
but, x is LESS THAN 90°, therefore, we are completely sure that the area of any triangle in that domain must be less than 18.

Option B


it is mentioned in question that
x is > 90.,
therefore ans should be A


Sorry, there is a typo in the last sentence (the option is still B). In the beginning, I exposed the opposite:

The area of any triangle with a x° angle in the domain of 90° < x < 180°, is less than the area of a triangle with x=90°
,

therefore, it should be: "x is MORE THAN 90°"

thanks!
Manager
Manager
Joined: 09 Nov 2018
Posts: 88
Own Kudos [?]: 95 [2]
Given Kudos: 0
Send PM
Re: The area of the circle above, with center C, is [#permalink]
2
Quote:
The area of the circle above, with center C, is 36π, and x>90

Step 1: Understanding the question
Area of the circle = π r^2 = 36π
r = 6

Area of a triangle is maximum when the triangle is a right angle triangle.

Step 2: Calculation
When x = 90, area of the triangle = 1/2 * 6 * 6 = 18
As x > 90, area of the triangle is less than 18

B is correct
Intern
Intern
Joined: 10 Jan 2020
Posts: 23
Own Kudos [?]: 26 [2]
Given Kudos: 40
Send PM
The area of the circle above, with center C, is [#permalink]
1
1
Bookmarks
All of the answers is write but with no proof. How did you know that the area is less when the angle is more than 90 degree?
Actually, the formula for the area of an isosceles triangle with sides a is a^2*Sinx/2. this is the reason.

Originally posted by amirbehani on 10 Jan 2021, 11:22.
Last edited by amirbehani on 12 Jan 2021, 10:41, edited 1 time in total.
avatar
Intern
Intern
Joined: 27 Dec 2020
Posts: 19
Own Kudos [?]: 16 [1]
Given Kudos: 0
Send PM
Re: The area of the circle above, with center C, is [#permalink]
1
Bookmarks
First step is to find the radius of circle.
pi*r^2 = 36*pi
r=6

Now we know area of triangle is 0.5*Base*Height.
If x had been 90, the area would have been 0.5*6*6=18, simply because the height and base are given for this particular scenario.
Now if we increase the angle x, the height reduces, thus if base value remains same, and height is decreasing, the area will also decrease.

Thus Qb>Qa
Intern
Intern
Joined: 10 Jan 2020
Posts: 23
Own Kudos [?]: 26 [0]
Given Kudos: 40
Send PM
Re: The area of the circle above, with center C, is [#permalink]
Quiqq wrote:
First step is to find the radius of circle.
pi*r^2 = 36*pi
r=6

Now we know area of triangle is 0.5*Base*Height.
If x had been 90, the area would have been 0.5*6*6=18, simply because the height and base are given for this particular scenario.
Now if we increase the angle x, the height reduces, thus if base value remains same, and height is decreasing, the area will also decrease.

Thus Qb>Qa


You are completely wrong. Math is the language of mathematic formulas not explanation. Moreover your explanation is also wrong, because when the angle x becomes greater, the base value also increases. you cannot say " if the base value remains the same".
Intern
Intern
Joined: 06 Dec 2021
Posts: 29
Own Kudos [?]: 25 [0]
Given Kudos: 169
Send PM
Re: The area of the circle above, with center C, is [#permalink]
amirbehani wrote:
Quiqq wrote:
First step is to find the radius of circle.
pi*r^2 = 36*pi
r=6

Now we know area of triangle is 0.5*Base*Height.
If x had been 90, the area would have been 0.5*6*6=18, simply because the height and base are given for this particular scenario.
Now if we increase the angle x, the height reduces, thus if base value remains same, and height is decreasing, the area will also decrease.

Thus Qb>Qa


You are completely wrong. Math is the language of mathematic formulas not explanation. Moreover your explanation is also wrong, because when the angle x becomes greater, the base value also increases. you cannot say " if the base value remains the same".


Sir, I believe you are wrong. Upon increasing the angle at the center above 90 degrees, the height does reduce, as the base will always remain same as the radius.
User avatar
GRE Prep Club Legend
GRE Prep Club Legend
Joined: 07 Jan 2021
Posts: 5006
Own Kudos [?]: 74 [0]
Given Kudos: 0
Send PM
Re: The area of the circle above, with center C, is [#permalink]
Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Prep Club for GRE Bot
Re: The area of the circle above, with center C, is [#permalink]
Moderators:
GRE Instructor
77 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
228 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne