Question

Mark all statements that are true.

A. An angle that measures 2π/3 is a reflex angle.
B. An angle that measure 170° is an obtuse angle.
C. An acute angle is one that measures less than π/2 but more than π/4.
D. An angle that measures 95° is an acute angle.

I know D. is NOT the answer and B. is ONE of the ANSWERS I am just not sure about A. and C.

Please help and explain. Thank you!

Answer 1

Absolutely correct D cannot be right. An acute angle is acute strictly because it is an angle of less than 90 degrees of measure.

Let's look at A.
What's a reflex angle?

Answer 2

I just learned it's an angle that is greater than one hundred and eighty degrees, and less than three hundred sixty.
- http://www.mathopenref.com/anglereflex.html
An obtuse angle is one measuring greater than ninety degrees.