Microsoft Office Tutorials and References
In Depth Information
Getting an Angle on Trigonometry
If the angles are in degrees, then they need to be converted into radians by
using the RADIANS function. In this case you would use these:
Which leads us to…
Degrees and radians
An angle can be expressed in degrees or radians. A degree is more common
to us non–rocket scientists. Most everyone know that there are 360 degrees
in a circle, or that a right angle is 90 degrees, or even that doing a “180”
means turning completely around and going the other way.
One radian = 180/pi degrees, and one degree = pi/180 radians. All this
talk about pi is making me hungry! For lowdown and quick conversion:
1 radian = 57.3 degrees.
Pi is approximately equal to 3.14159. See the beginning of this chapter for a
forkful of pi.
Excel provides the RADIANS and DEGREES functions to convert a number
from radians to degrees or vice versa. I think the real reason they did this
was to keep pi out of the picture so we would concentrate on work and not
The functions are the single argument type:
=RADIANS(angle in degrees)
=DEGREES(angle in radians)
Using some numbers, we can see that 90 degrees = 1.5707963267949 radians
and so 1.5707963267949 radians must equal 90 degrees. And it does.