Three fences of a triangular garden meet pairwise at the three corner posts and

MATHEMATICS · Subjective · CBSE · Mathematics · Introduction to Euclid's Geometry · Introduction to Euclid's Geometry

Problem

Three fences of a triangular garden meet pairwise at the three corner posts A, BA,\,B and CC. A gardener insists that two of these fences, say ABAB and ACAC, also meet at an interior point DD inside the garden. (a) Explain why the gardener’s statement leads to a contradiction with Euclid’s theorem on common points of two lines. (b) Give a logically complete proof that no interior point like DD can exist which lies simultaneously on extensions of both fences ABAB and ACAC if ABAB and ACAC are regarded as straight lines.

Related theory

Browse the problem library