MathDB
n equal parts in AB, n+1 equal parts in AC, coloring triangles, area wanted

Source: Sharygin 2005 X-XI CR 6

August 18, 2019
geometryarea of a triangleareas

Problem Statement

Side ABAB of triangle ABCABC was divided into nn equal parts (dividing points B0=A,B1,B2,...,Bn=BB_0 = A, B_1, B_2, ..., B_n = B), and side ACAC of this triangle was divided into (n+1)(n + 1) equal parts (dividing points C0=A,C1,C2,...,Cn+1=CC_0 = A, C_1, C_2, ..., C_{n+1} = C). Colored are the triangles CiBiCi+1C_iB_iC_{i+1} (where i=1,2,...,ni = 1,2, ..., n). What part of the area of the triangle is painted over?