Answer:
AE and BD use the same lines for both triangles so the angles for C are the same. this means that all the angles are congruent between both triangles.
Step-by-step explanation:
The distance across the river d=175ft
As◇ ABC& ◇ EDC are similar, BC/CD=AB/ DE
4x/7x=100/d
d=100×7/4=175
