Answer
$$c=8.90cm$$
Work Step by Step
This is a right triangle. This means we can use the Pythagorean Theorem to find the length of the hypotenuse.
The formula is $c=\sqrt (a^{2}+b^{2})$
In this case,
$a=8.00cm$
$b=3.90cm$
So,
$c=\sqrt (8^{2}+3.9^{2})$
$c=\sqrt (64+15.21)$
$c=\sqrt 79.21$
$c=8.90cm$
