Problems about congruence of line segments, angles, and triangles.
Level: High School, SAT Prep, College geometry.
Extension Cyclic Quadrilateral: Ratio of the Diagonals.
(An Old Japanese Theorem)
Let a convex inscribed polygon be
triangulated in any manner, and draw the
to each triangle so constructed. Then the sum of the
is a constant independent of the triangulation chosen.
45. Sangaku Problem 2.
3 circles of radiii:
tangent to each other and a line
Semiperimeter and excircles of a triangle
Semiperimeter and incircle of a triangle
Semiperimeter and incircle and excircles of a triangle