Discussion

Question:

A square of side 's' units is cut down into a regular octagon. What is the side of the regular octagon?

Explanation:

We will have to cut a right angled triangle from the 4 corners of the square to form an octagon. 

Let 'a' be the side of the right angled triangle, such that the hypotenuse of the right angled triangle be the side of the octagon.

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a + √2a + a = s

⇒ $a=\frac{s}{2+\sqrt{2}}$

⇒ $\sqrt{2}a=\frac{s}{\sqrt{2}+1}$

Hence, option (c).

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