According to legend,one of Napoleon’s officers used congruent triangles to estimate the width of a river. On the riverbank, the officer stood up straight and lowered the visor of his cap until the farthest thing he could see was the edge of the opposite bank. He then turned and noted the spot on his side of the river that was in line with his eye and the tip of his visor. Given & DEG and &DEF are right angles & EDG & EDF .The officer then paced off the distance to this spot and declared that distance to be the width of the river! Use congruent triangles to prove that he was correct.