Online Geometry: Triangles, Theorems and Problems

Triangles Theorems and Problems- Page 22

Proposed Problem 51: Fagnano's Problem
Inscribed Triangle with the Minimum Perimeter.

Lunes of Hippocrates 4
Right triangle. 

Lunes of Hippocrates 3
Right triangle. 

Lunes of Hippocrates 2
Right triangle. 

Lunes of Hippocrates 1
Right triangle. 

Pythagoras and Circle Area
Right triangle. 

Right Triangles, Formulas and Facts
Pythagorean theorem, Similarity, Geometric mean, hypotenuse, cathetus (legs), semiperimeter, altitude, median, similar shapes areas, centers, orthocenter, incenter, centroid, circumcenter, radius, inradius, circumradius, exradius, circles, incircle, circumcircle, excircle.

Triangle and Squares 21
See also: Triangle and Squares 19

Triangle and Squares 20

Proposed Problem 50. Triangle with Equilateral triangles.
Seventeen conclusions.

Proposed Problem 49. Angles and right triangle.