Dx
mark the statements that are true

a. an angle that measures 2.5 radians is an acute angle.
b. an angle that measures 3.5 radians is an obtuse angle.
c. an acute angle measures less than 90.
d. an angle that measures 285 is a reflex angle.

We need to convert radian to degree.

1 radian = 57.2958 degrees

a) An angle that measures 2.5 radians is an acute angle. FALSE

2.5 radians = 143.239 degrees.
an acute angle is an angle that is less than 90°. So, 2.5 radians is NOT an acute angle. 

b) An angle that measures 3.5 radians is an obtuse angle. FALSE

An obtuse angle is more than 90° but less than 180°
3.5 radians = 200.535 degrees.

c) An acute angle measures less than 90°. TRUE

d) An angle that measures 285° is a reflex angle. TRUE

A reflex angle is more than 180° but less than 360°