In 1846 the depth of the river was 5 feet deep. In 1847 it dropped to 4.5 feet. This year, 1848, it rose to 5.3 feet. Find the percent change in river depth

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.