MathDB

5

Part of 1997 Portugal MO

Problems(1)

total sum of line segments >70 in a square of side 12, 1997 Portugal p5

Source:

10/11/2020
A square region of side 1212 contains a water source that supplies an irrigation system constituted by several straight channels forming polygonal lines. Considers the source as a point and each channel as a line segment. Knowing that a point is irrigated if it is not more than 11 distance from any channel and that the system was designed so that the entire region is irrigated, proves that the total length of irrigation channels exceeds 7070.
geometryLine segment