Verified answer

First, let's derive the half-angle formula for tangent

tan(m/2) =>

sin(m/2) / cos(m/2) =>

sqrt((1/2) * (1 - cos(m))) / sqrt((1/2) * (1 + cos(m))) =>

sqrt(1 - cos(m)) / sqrt(1 + cos(m)) =>

sqrt((1 - cos(m))^2) / sqrt(1 - cos(m)^2) =>

(1 - cos(m)) / sqrt(sin(m)^2) =>

(1 - cos(m)) / sin(m)

m/2 = 345

m = 690

690 - 360 => 330

(1 - cos(330)) / (sin(330)) =>

(1 - sqrt(3)/2) / (-1/2) =>

((2 - sqrt(3)) / 2) / (-1/2) =>

sqrt(3) - 2