Question 2
Let $R,r$ be the radii of the circumscribed and inscribed spheres of a regular $1986$-gonal pyramid.
(a) Prove that $\displaystyle\frac Rr\ge1+\frac1{\cos(\pi/1986)}$.
(b) Find its lateral surface area if its base side is $a$ and equality holds.
(a) Prove that $\displaystyle\frac Rr\ge1+\frac1{\cos(\pi/1986)}$.
(b) Find its lateral surface area if its base side is $a$ and equality holds.