Sin(alpha)/sin(beta)=n
sin(beta)=sin(alpha)/n
beta=asin(sin(alpha)/n)=asin(sin(40*pi/180)/1,5)=
0,44286 рад =
25,37399
град
CK=h*tg(alpha)
CB=h*tg(beta)
BK=CK-CB=h*(tg(alpha)-tg(beta))
d=BK*cos(alpha)=h*(tg(alpha)-tg(beta))*cos(alpha) =
=28*(tg(40*pi/180)-tg(0,44286))*cos(40*pi/180)=
7,825124 ~ 8