#### Answer

Obtuse Triangle

#### Work Step by Step

Using the Pythagorean Theorem...
$a^{2}+b^{2}=c^{2}$
$3^{2}+8^{2}=15^{2}$
Simplify...
$9+64=225$
$73=225$
Since the sum of the sides squared $(73)$ is less than the hypotenuse squared $(225)$, the triangle is an obtuse triangle.