SOLUTION: A compass of length 9cm is being used to draw a circle of radius 2cm. At what angle must the arms be opened?

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Question 1123205: A compass of length 9cm is being used to draw a circle of radius 2cm. At what angle must the arms be opened?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Is this a trig question?
If so,
The compass makes an isosceles triangle
that is 9-9-2
when it’s ready to trace a 2 cm radius circle
Drop a perpendicular from top
The angle compass makes with paper is defined as
+cos%28+theta+%29+=+1%2F9+
+theta+=+83.62+ degrees
If +beta+ is the top angle, then
+beta+%2F2+=+90+-+83.62+
+beta%2F2+=+6.38+
+beta+=+12.76+ degrees is
angle to spread the arms