Angle of array problem

Hi can someone help me please im very frustrated with angle array, im trying this but keep going 1 arrayed item outside the 180 deg.

Heres how the book wants it.

1. all parts pline

2. line weight 0.7

2. centre point 180,120

3. arc with R90 facing north or 12 oclock

4. arc with R10 to be arrayed 16 times around the R90 arc, offset of 10 from arc

6. angle to be filled 180degs or -180degs ?

7. rotate items as copied

in theory the R10 arcs should end at the other side of the R90 arc but they keep going 1 past the end, very frustrating im positive im doing this correct but keep getting the wrong result, when i try arraying to 360 degs it works perfect.

i hope this makes sense and it is a glaring mistake on my behalf.

Andy:huh:

Are the arcs 90 degree or 180 degree?

I just tried both options and seems Ok

Can you upload a screen capture of what you have, and I will see if I can help

It works fine here, if you are giving an angle to fill of 180 then that is what it will do. You must be using some other options and giving an angle between, maybe. In step 4 I am not sure what the "offset of 10 from arc" means.

In step 4 I am not sure what the "offset of 10 from arc" means.

after drawing the small arc move it out 10 units then array it

hi point 4 "offset" was just saying that the small r10 arc had to be sitting 10 of the main r90 arc, i will try constructing the r10 arc on the r90 arc then offsetting it by 10.

As for why it keeps going 1 arc past 180 i still have no idea ???¿¿¿¿???

its a bit difficult for uploading a screen shot as im abroad just now and have no internet at the apartment.

angle to be filled 180degs or -180degs

That's the determining factor, unless you've specified a distance between the items.