I don’t understand this subject at all if you wold answer that would be a big help

Answer:
d is about 8.6 feet.
Step-by-step explanation:
We have similar triangles, so we can set up and then solve this proportion:
[tex] \frac{d}{10} = \frac{6}{7} [/tex]
[tex]7d = 60[/tex]
[tex]d = 8.6[/tex]