Answer
$d \approx 8.1$ units
Work Step by Step
1. Use the cosine ratio to find $d$
Recall that CAH: $cos = \frac{adjacent}{hypotenuse}$
$cos(36) = \frac{d}{10}$
$d = 10cos(36)$
by GDC / calculator
$d = 8.09016...$ units
$d \approx 8.1$ units