它移么平学院 解由图可得 P=AOB=AB+AB P B解 由图可得 ABC ABC AB AB AB C AB C QR AB AB C AB Q PC AB AB C R AB ABC ABC ABC ABC AB AB C AB AB C S P C AB AB C P A B AB AB i i i i i i i i i i i i i i i = + + = + + = = + = = + = = + + + = + + + = = + = = + + _ _ _ _ _ _ _ _ ____ _ _ _ _ ___ 1 ____ _ _ _ _ ____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ( ) ( ) ( ) ( ) ( ) ( ) & & & Q R A = 1 = 1 B Ci Ci+ 1 P S