Question

You need to find the width of the stream. You cannot measure the width directly, so you draw a diagram showing lengths that you can measure. Your diagram contains two similar triangles, one in the stream and one on land. Use the diagram to find the width of the stream.

Answer 1

I believe it is a) 22.4 feet.  I looked at the comparison between the 6 feet and the width of the lake and a) seemed to make the most sense.

Answer 2

You are given that the diagram contains two similar triangles.

Two similar triangles have proportional sizes of corresponding sides.

Then the ratio between smaller legs is the same as the ratio between greater legs:

$\dfrac{x}{6}= \dfrac{28}{7.5},\\ \\x=\dfrac{28\cdot 6}{7.5}=22.4\ ft.$

Answer: correct choice is A.