What is the distance across the river?

Answer:
The correct answer is,
d = 300 feet
Step-by-step explanation:
Points to remember
The ratio of of corresponding sides of similar triangles are equal.
From the figure we can see two similar triangles.
To find the value of d
It is given that, the ratio of d to 150 ft is the same as the ratio of 40 ft to 20 ft
d/150 = 40/20
d = (150 * 40)/20
d = 300
Therefore the value of d = 300 ft