Question

What angle measure, in radians, corresponds to a central angle of 180° in a circle with a radius of 2 units?

Select one:

a.pi /2

b. pi./4

c. pi

d. 2pi

Answer 1

180 degrees is the same as pi radians.

Explanation:

In order to convert angles from degrees to radians we must, apply the following formula:

rad = degree*pi/180

Since degree in this case is 180, we have:

rad = 180*pi/180 = pi

So the answer is "c". We must notice that the radius of the circle won't change the central angle, it doesn't matter how big or small the circle actually is, we can simply apply the formula for the conversion.