Counting triangles in ISI Entrance

Get motivated… try this quiz

Understand the problem

Let P be a regular 12 sided polygon. How many right triangles can be formed by the vertices of P?

Tutorial Problems… try these before watching the video.

1. Show that a regular 12 sided polygon must be cyclic.
2. Show that hypotenuse of any right triangle, whose vertices are vertices of the above polygon, must be diameter of the circle (in which the polygon is inscribed)

You may send solutions to support@cheenta.com. Though we usually look into internal student's work, we will try to give you some feedback.

Now watch the discussion video

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