The pillar is driven into the bottom of the river and rises 1 m above the water. Find the length of the shadow of the pillar

The pillar is driven into the bottom of the river and rises 1 m above the water. Find the length of the shadow of the pillar at the bottom of the river, if the height of the Sun above the horizon is 30, the depth of the river is 2 m, and the refractive index of the water is 1.33.

sin L / sin j = n2 / n1 sin 60 / sin j = 1.33
sin j = 0.86 / 1.33 = 0.64
arcsin 0.64 = 40
AC = tg 30 = 1.7
DE = ctg 40 = 0.2
It turns out that DO = 1.7 + 0.2 = 1.9 m