Tolong di kerjakan. Bantu saya tolong.

a. Besar semua sudut segitiga 180°,
A + B + C = 180°
A + 30° + 90° = 180°
A = 180° - 120° = 60°
Tan 60° = CD/AD = t/8
t = 8 tan 60° = 8√3
AC = √(8^2 + (8√3)^2) = √(64 + 192)
AC = √256 = 16
BC= t/sin 30°
BC = 2t = 2(8√3) = 16√3
BD = √((16√3)^2 - (8√3)^2)
BD = √(768 - 192) = √576 = 24
AB = AD + DB = 8 + 24 = 32
Keliling segitiga ABC adalah:
AB + BC + AC = 32 + 16√3 + 16 = 16(3 + √3) cm

b. Luas segitiga ABC = 1/2 AB × CD = 1/2 32 × 8√3 = 128√3 cm persegi