Online Geometry
Problem 470. Triangle, Parallel, Parallelogram, Area,
Similarity
The figure below shows a triangle ABC
of area S, DE parallel to AC and EF parallel to AB. If S1,
S2, and S3 are the areas of triangle DBE,
triangle CEF, and parallelogram ADEF respectively, prove that
(1)
,
(2)
.
,
(2)
.