如图,△ABC中,AB=AC,BE⊥AC于E,且D、E分别是AB、AC的中点.延长BC至点F,使CF=CE.
(1)求∠ABC的度数;
(2)求证:BE=FE;
(3)若AB=2,求△CEF的面积.
如图,△ABC中,AB=AC,BE⊥AC于E,且D、E分别是AB、AC的中点.延长BC至点F,使CF=CE.
(1)求∠ABC的度数;
(2)求证:BE=FE;
(3)若AB=2,求△CEF的面积.
解:(1)∵BE⊥AC于E,E是AC的中点,
∴△ABC是等腰三角形,即AB=BC,∵AB=AC,∴△ABC是等边三角形,
∴∠ABC=60°;
(2)∵BE=FE,∴∠F=∠CEF,∵∠ACB=60°=∠F+∠CEF,∴∠F=30°,
∵△ABC是等边三角形,BE⊥AC,∴∠EBC=30°,∴∠F=∠EBC,∴BE=EF;
(3)过E点作EG⊥BC,如图:
∵BE⊥AC,∠EBC=30°,AB=BC=2,
∴BE=,CE=1=CF,
在△BEC中,EG=,
∴.