A plant's length (in centimeters) as a function of
time (in weeks) is graphed.
What is the approximate average speed at
which the plant's length increases, between the
2nd and the 18th week marks?
eters)

Given: ae ≅ ce ; de ≅ be prove: abcd is a parallelogram. we have that ab || dc. by a similar argument used to prove that △aeb ≅ △ced, we can show that △ ≅ △ceb by. so, ∠cad ≅ ∠ by cpctc. therefore, ad || bc by the converse of the theorem. since both pair of opposite sides are parallel, quadrilateral abcd is a parallelogram.