how to do a loop in a calculation

[ged]

hi i need to do a loop for my following code to increase my number of sides by one till the sin is less than pi and pi is less than tan or sin and tan are both equal to pi. do i start my loop from the int sides = 4 by using the ++ sin <pi <tan .
could you give me a hint in the right direction as i want to learn

import java.math.*;
import java.io.*;
class ged1loop
{
public static void main(String [] args)throws IOException
{
int sides = 4;
System.out.println("the angle of "+ sides+" sides is "+(180/sides) );
double n = (180/ sides);
System.out.println("Sine is: " +Math.sin (Math.toRadians(n)));
System.out.println("Tangent is: " +Math.tan (Math.toRadians(n)));
System.out.println("Sine times by sides : " +Math.sin (Math.toRadians(n))*sides);
System.out.println("Tangent times by sides is: " +Math.tan(Math.toRadians (n))*sides);
}
}

[Daok]

Search in your book about : IF and ELSE statement

[ged]

i have read my book from back to front, on loops it is easy to do a loop to increase the number of sides. i have done that. But the book don't mention how i can do a loop so that my adding number of sides will stop when the answer for sin is less than PI and also PI is less then TAN answer. eg when i run a loop say to increase the numbers sides up to 50. i would want it to stop at sides 48 as this would be right. sin< PI < tan
sides 49 sin <PI but the tan is not
the sin for 48 sides is 3.13950 ect which is less than PI
the tan for 48 sides is 3.14608 ect which is greater than PI

sides 49 sin is less than PI, but the Tan is less as well, which is no good. my answer would have to finnish with 48 sides

the book has no examples for what i need or how to write it.

i don,t mind learning myself, maybe i picked a hard one to figure out for a beginner. But if any one can recommend a book that will explain this. i will go and get it.

thanks for your time, as i'm not pushing for the answer that would be lazy. just for help were i can read up on how if at all it is possible.

[marnitzg]

I'm guessing that you need something like this. Although I'm not sure how you got the values for sin and tan

for (sides = 4; (Math.sin(Math.toRadians (sides)) >= Math.PI) || (Math.tan(Math.toRadians(sides)) <= Math.PI); sides++)
{
...
}

If you want it to stop before 50 then just add && sides <= 50

In degrees sin 48 = 0.743144825
In radians sin = -0.768254661
in radians sin(180/48) = -0.571561318

So I'm not too sure how you're calculating your numbers, but you should be able to replace your method in the for loop
|| = or
&& = and

Hope that helps

[ged]

thanks a million, i was about to lash the computer throu the windon. the sum i was working on was Archimedes Method. you are right over sin and tan its just that i had to multiply sin and tan again by number of sides. Good job Mr Arcimedes is dead as i would have killed him i was never good at maths.
thanks again, no longer will i wake up in the middle of the night trying codes that was sending me mad!

[marnitzg]

Ahh, makes more sense now. Glad to be of some help