Let △ A B C and E, D on [ A B ] and [...
Let and E, D on and s.t. BEDC is inscribable. Let , s.t. AEPC and ADQB are also inscribable. Show that .
Answer & Explanation
In the same way:
as mentioned in comment.I made two drawings, one isosceles. These points are noticeable:
The measure of the sides and angles of isosceles triangle APQ does not vary with the type of triangle.
It can be assumed as a kind of affine transformation. Because base of triangle is fixed and the location of vertex A alters. It is like moving a triangle APQ relative to the base of ABC to construct three circles with certain measures of diameter.