Question 859564
{{{drawing(300,300,-10,10,-10,10,circle(0,0,5),line(0,0,0,-3.25),line(0,0,4.75,0))}}}
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{{{drawing(300,300,-10,10,-10,10,circle(0,0,5),line(0,0,0,-3.25),line(0,0,4.75,0),green(line(0,0,0,-5)),green(line(0,0,5,0)),green(line(0,0,0,-1)),green(line(0,0,1,0)),green(line(1,0,1,-1)),green(line(1,-1,0,-1)))}}}
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It splits the circle into 4 parts.
The whole circle has 360 degrees. 
One quarter of that would be 90 degrees.