Friday 22 October 2010

Two Grand Question

(You are not required to write a new post about this.)

I hope the field trip is an eye-opening experience. The Two Grand Question is doable than some other questions. I enourage you to try it. Let me know you did it before Tuesday and you win two small chocolates from Mr. Cheng!

Here is the question:
3 identical circles with radius r are touching (tangent) each other and inscribed in a larger circle as shown. What is the radius of the large circle in terms of r?


To solve this question, you need to use:
1) symmetry to draw triangles to help you find large radius
2) sin 30 degree = 1/2 = opp/hyp
3) Pythagorean Theorem

No comments:

Post a Comment