Lesson: Pieces of Pi

Comment on Pieces of Pi

https://gmatclub.com/forum/the-points-r-t-and-u-lie-on-a-circle-that-has-radius-4-if-168676.html

I am confused by the question. I understand the concept of circumferences and got the bit that the arch 1/6 of the circle. But, at what point in the question did it say that points RTU make up a triangle? Points RTU could be three separate points on the circumference of the circle - couldn't it?

What am I missing here?
gmat-admin's picture

Question link: https://gmatclub.com/forum/the-points-r-t-and-u-lie-on-a-circle-that-has...

You're right to say that the arc is 1/6 of the circle.
This means the central angle of ∆RCU is 60°

Take a look at the image Bunuel created at https://gmatclub.com/forum/the-points-r-t-and-u-lie-on-a-circle-that-has...

Since the central angle of ∆RCU is 60°, we can see that ∆RCU is an EQUILATERAL triangle.
Since all sides are equal in an equilateral triangle, each side has length 4.

Does that help?

Cheers,
Brent

Add a comment

Office Hours

Have questions about your preparation or an upcoming test? Need help modifying the Study Plan to meet your unique needs? No problem. Just book a Skype meeting with Brent to discuss these and any other questions you may have. 

Change Playback Speed

You have the option of watching the videos at various speeds (25% faster, 50% faster, etc). To change the playback speed, click the settings icon on the right side of the video status bar.

Have a question about this video?

Post your question in the Comment section below, and I’ll answer it as fast as humanly possible.

Free “Question of the Day” emails!