Which number is the least 0.092, 0.029, 0.043

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c.then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and pointc are collinear. she marks point e at this location, as shown.(a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?