MathDB
sum of angles <1100^o, driver + fence (2017 Novosibirsk Oral Geo Oly 8-9 p7)

Source:

April 26, 2021
geometryangles

Problem Statement

A car is driving along a straight highway at a speed of 6060 km per hour. Not far from the highway there is a parallel to him a 100100-meter fence. Every second, the passenger of the car measures the angle at which the fence is visible. Prove that the sum of all the angles he measured is less than 1100o1100^o