Answer
The unknown length is $9.2$ cm long.
Work Step by Step
1. Use the Pythagorean Formula to solve for the missing length
$a^{2} + b^{2} = c^{2}$
$c^{2} = 7^{2} + 6^{2}$
$c^{2} = 49 + 36$
$c^{2} = 85$
$c = \sqrt 85$
$c = 9.2195...$ cm
$c = 9.2$ cm
