‰‰K‰đ“š@i•¨—‚Q ƒoƒCƒI‚P”NA‘gj

 

ƒ‚P‚QŒŽ‚Q‚O“úi‹ŕj„

tanƒĆB = n ‚ć‚čCƒĆB = 54.7‹

ƒĆt = ƒÎ/2 -ƒĆB = 35.3‹