Obtuse triangle
Source: Canada 1970, Problem 2
May 14, 2006
trigonometry
Problem Statement
Given a triangle with angle obtuse and with altitudes of length and as shown in the diagram, prove that . Find under what conditions .
[asy]
size(6cm);pair A = dir(105), C = dir(170), B = dir(10), D = foot(B, A, C), E = foot(A, B, C);draw(A--B--C--cycle);
draw(B--D--A--E);dot(A); dot(B); dot(C); dot(D); dot(E);label("", A, dir(110));
label("", B, B);
label("", C, C);
label("", D, D);
label("", E, dir(45));label("", A--E, dir(0));
label("", B--D, dir(45));
[/asy]