Online Geometry

Geometry: Incenter, Incircle, Inradius of a triangle, Theorems and Problems.

Incenter, Incircle, Index


Napoleon Theorem II

Proposed Problem 247.
Napoleon's Theorem II. Internal Equilateral triangles. Inner Napoleon triangle.

Napoleon Theorem I

Proposed Problem 246.
Napoleon's Theorem I. External Equilateral triangles.

Right triangle, inradius, altitude, arithmetic mean

Proposed Problem 220 Incenter. Right Triangle, Altitude, Angle Bisector, Distance, Arithmetic Mean.

Elearn: Quadrilateral, Angle Bisectors, Concurrency

Proposed Problem 216 Incenter, Excenter. Quadrilateral, Angle Bisectors, and Concurrency.

Elearn 215: Cyclic quadrilateral

Proposed Problem 215. Quadrilateral, Angle Bisectors, and Cyclic Quadrilateral.

Elearn 213 Triangle Inradius, Common Tangents

Proposed Problem 213. Triangle, Incircle, Inradius, Semicircles, Common Tangents.

Elearn 209

Proposed Problem 209. Triangle, Incircles, Inradius.

Problem 207: Hypotenuse

Proposed Problem 207. Right Triangle, Hypotenuse, Incenter, Inradius, Exradius relative to the hypotenuse.  

Elearn 206

Problem 206. Area of a Right Triangle, Inradius, and Exradius relative to the hypotenuse.  

Elearn 204

Proposed Problem 204. Right Triangle, Incircle, Excircles, Inradius, Exradii.  

Problem 202 Right triangle, excircles

Proposed Problem 202. Right Triangle, Incircle, Excircles relatives to catheti, Points of Tangency, Exradius, Semiperimeter.  

Elearning 200: Right Triangle

Proposed Problem 200. Right Triangle, Incircle, Excircles, Points of Tangency, Inradius.

Elearning 197: Triangle Area

Proposed Problem 197. Area of a Triangle, Side, Incircle, Inradius, and Exradius.

Elearning 196: Inradius, Exradii

Proposed Problem 196. Triangle, Incircle, Inradius and Exradii Formula.

Triangle Centers Video

Journey to the Center of a Triangle (1976), Video.
Incenter, Circumcenter, Centroid, Orthocenter.

Geometry: Triangle Area, inradius, exradii

Proposed Problem 195. Area of a Triangle, Incircle, Inradius, Exradii.  

Area of a triangle, semiperimeter, inradius

Proposed Problem 193. Area of a Triangle, Semiperimeter, Inradius.

Elearning 187: Right triangle, incircles, angles

Proposed Problem 187. Right Triangle, Altitude, Incenters, Circles, Angles.  

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Home | SearchGeometry | Triangle Centers | Post a comment | Email | By Antonio Gutierrez
Last updated: Mar 9, 2022