8. If $\odot O$ is inscribed in $\triangle A B C$ and touches the three sides at points $X, Y, Z$. Then, $\triangle X Y Z$ satisfies ( ).
(A) Each angle is equal to $60^{\circ}$
(B) One is an obtuse angle, the other two angles are acute
(C) It is similar to $\triangle A B C$
(D) Each angle is equal to half the sum of two angles in $\triangle A B C$