The result for a sum of all interior angles for #N#-sided convex polygon is #N*180^o - 360^o = (N-2)*180^o# In #N#-sided regular polygon all #N# angles are equal, so each is equal to #((N-2)/N)*180^o# For #N=9# this gives a measure of one interior angle of a regular 9-sided polygon: #((9-2)/9)*180^o = 140^o#
The intrinsic, or gross, value of an option is the amount the option is in the money. For example, if you have the option to pay $10 per share for a stock that trades for $15, the option has an intrinsic value of $5 per share.
In your example, buying a $4 strike call option on a stock that is trading at $7 would be worth at least $3 in premium, let's say $3.50. Buying 1 call option contract would cost you $350 (100 shares) and this option's price changes are likely to move in line with the stock. long call option is the simplest way to benefit if you believe that the market will make an upward move and is the most common choice among first time investors.