Minimum Arc Distance

OJ: lightoj

problem no: 1433
* need to find  ACB.

We know, S = r * Θ     ; Here S = ABC, r = OA  = i = OB = k, Θ = <AOB;

Step: 01) Find  , OA = i, AB = j, BO = k (using O, A, B coordinate)

Step: 02) Find , <AOB :(use the formula down below)

cos Θ = (i*i + k*k - j*j) / (2*i*k);


Now, S = r * <AOB

so, S = i * <AOB

 

__MD. SAMIUL ISLAM