A ladder is to be placed 3 feet from the side of the house. If the top of the ladder rest exactly on the edge of the house when it is placed at an angle of 72 degrees from the ground, how long is the ladder to the nearest foot?

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.