Navigation 
 Home 
 Search 
 Site map 

 Contact Graeme 
 Home 
 Email 
 Twitter

 Skip Navigation LinksMath Help > Geometry > Polygons and Triangles > Apollonius' Theorem

Apollonius' theorem states that given a triangle ABC, if D is any point on BC such that it divides BC in the ratio n:m (or mBD = nDC), then

mAB2 + nAC2 = mBD2 + nDC2 + (m + n)AD2

Proof:

. . . . . . add an image here, as well as a proof.

Internet references

Wikipedia: Apollonius' theorem

Related pages in this website:

Summary of geometrical theorems

 

The webmaster and author of this Math Help site is Graeme McRae.