An observer spots a plane flying at a 42 degree angle to his horizontal line of sight. if the plane is flying at an altitude of 15,000 ft, what is the distance (x) from the plane (p) to the observer (o)

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.