Tiffany N. KeysŐ Essay 3:

Trisection of the Area of a Triangle


Given a triangle ABC, find a point D such that line segments AD, BD, and CD trisect the area of the triangle into three regions with equal areas. Define D and prove that the triangle is divided into three regions of equal area. Show a construction for finding D



Triangle BCD and the segment CE which is a median of triangle ABC were constructed.

The area of triangle BCD = 1/2bh.  Therefore the area of triangles BCA, CAD, and BAD will be 1/3 the area of triangle BCD, or 1/3 × 1/2bh = 1/6bh.

In order to trisect the area of triangle BCD, I constructed a point A such that segment AE that was 1/3 the length of segment CE.

The point A that divides the median of a triangle in the ratio of 2 : 1 is called the centroid of a triangle.





Return to Tiffany N. KeysŐ Homepage