What is an angle which measures \[\text{180 }\!\!{}^\circ\!\!\text{ }\]called?

What is an angle which measures \[\text{180 }\!\!{}^\circ\!\!\text{ }\

1.	What is an angle which measures \[\text{180 }\!\!{}^\circ\!\!\text{ }\]called?
A.	A zero angle
B.	A right angle
C.	A straight angle
D.	An acute angle
Answer» D. An acute angle