## Trigonometry 7th Edition

8a) θ = 90$^{\circ}$ 8b) θ = 180$^{\circ}$ 8c) 0$^{\circ}$ $\lt$ θ $\lt$ 90$^{\circ}$ 8d) 90$^{\circ}$ $\lt$ θ $\lt$ 180$^{\circ}$
A right angle equals to 90$^{\circ}$, a straight angle equals to 180$^{\circ}$, an acute angle is between 0$^{\circ}$ and 90$^{\circ}$, an obtuse angle is between 90$^{\circ}$ and 180$^{\circ}$.