延长BP交AC于E,
AD是∠BAC的平分线,BP⊥AD,∴△ABE是等腰三角形,AB=AE,BP=EP,∠ABE=∠AEB
∴BE=BP+EP=2BP,又EC=AC-AE=AC-AB=2BP
∴△EBC是等腰三角形,∠EBC=∠C
∴∠ABC=∠ABE+∠EBC=(∠EBC+∠C)+∠EBC=3∠C
延长BP交AC于E,
AD是∠BAC的平分线,BP⊥AD,∴△ABE是等腰三角形,AB=AE,BP=EP,∠ABE=∠AEB
∴BE=BP+EP=2BP,又EC=AC-AE=AC-AB=2BP
∴△EBC是等腰三角形,∠EBC=∠C
∴∠ABC=∠ABE+∠EBC=(∠EBC+∠C)+∠EBC=3∠C