2.(1) (2) (3)分別為多少?

AE^2 + EG^2 = AG^2
∴ EG = √(10^2-5^2) = 5√3
   ∠GAE = 60° (∠AGE = 30°)
AH 是 ∠GAE 之平分線,
∴ ∠HAB = ∠HAG = 30°,
   ∠AHB = 60°
∴ GH = AH/2
   AG = 10 = √[AH^2-(AH/2)^2]
      = AH(√3/2)
∴ AH = 10/(√3/2) = 20/√3
△AGH 周長 = AG + AH + GH
    = 10 + 20/√3 + 10/√3
    = 10 + 30/√3 = 10(1+√3)
△AGH 面積 = (1/2)(AG)(GH)
    = (1/2)(10)(10/√3) = 50/√3
∵ △AGH 全等於 △ABH,
∴ ∠AHG = ∠AHB = 60°
∴∠GHC = 180° - ∠AHB - ∠AHG
        = 60°