Question

Mohon dibantu yah;)
Thx.

Answer 1

Nomor 10
Sudut pelurus A = 130°
Jadi: ∠A = 180° - 130° = 50°

Jumlah sudut dalam Δ = 180°
∠A + ∠B + ∠C = 180°
50° + 4x + 6x = 180°
10x = 180° - 50°
  x = 130°/10
  x = 13°

∠C = 6x = 6 x 13 = 78° (C)
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Nomor 11
Jumlah sudut segi-4 = 360°
Jadi
∠A + ∠F + ∠E + ∠D = 360°
38° + 90° + ∠E + 90 = 360°
               ∠E = 360° - 218°
               ∠E = 142°   (C)