1. The problem statement, all variables and given/known data A lamp is placed in the center at the bottom of a 2m deep swimming pool. The lamp emits light in all directions. Starting from a point directly above the lamp, a man in a canoe paddles until he no longer can see the lamp. How far did he paddle the canoe? Assume that the sides of the pool do not reflect light. n(water) = 1.33 n(air) = 1 2. Relevant equations Total internal reflection: θc = sin-1 n(air)/n(water) 3. The attempt at a solution I've found that the critical angle is θc = 48.75. However, I cannot seem to find the similar triangles required to find the distance.