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 |
|