Quit #100, okay now what does this mean?

[GillaMobster]

I keepgetting the error

Quit #100

on this line of code

code:

angle := arccosd ((reference ** 2 + longest ** 2 - distance ** 2) / (2 * reference * longest))

Can you tell me what the error means?

[AsianSensation]

what type did you declare for each variable?

angle should be a real

reference and longest should never have a value of 0

also, the value inside the arccosd() function should never be greater than 1 and less than -1