You want to find the width, AB, of a river. You walk along the edge of the river 100 ft and mark point C. Then
you walk 22 ft further and mark point D. You turn 90° left and walk until your location, point A, and point C are
collinear. You mark point E at this location, as shown.

(a) Suppose DE = 42 ft. What can you conclude about the width of the river? Explain. Your explanation
should include the approximate width and how you got this answer.
(b) Can you conclude that △ and △ are similar? Why or why not?