51.
Seven Circles
Theorem
53. Angle
between two Simson lines Proof 
54.
Steiner's Theorem.
Proof 
55.
100° Isosceles Triangle Problem 
56.
Triangles
57.
Triangle with the
bisectors of the exterior angles.
Collinearity
58.Triangle
and squares. 19 theorems, visual
illustrations.
59.
Triangle
with Squares 0 Two squares.
60. Triangle with Squares 1: Two squares
Proof 
