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is equal to the radius, and li=kg— 2Mg; or li=km-mg. 
FG being parallel to bc, and confequently perpendicular 
to ic, muft divide the chord lc in two equal parts; fo 
that MC being equal to ke, lc muft be equal to 2KE ; but 
KE (by EUCL. 1. XIII. pr. 12 . cor. 2 . Clav.) is equal to 
ED ; therefore lc = kd the radius. The fide of the 
fquare ic being equal to bc is like wife equal to nm ; but 
LC being equal to kg, the remaining part li muft be 
equal to NK— mg; or to KM— MG. ^E,D, 
XXVIII. 
