Plis Jawaaab ; ( Hehehehe ) ;

jumlah besar sudut ABD = 180°
<A + <B+<D = 180°
35° + 4x + ( x - 10) = 180°
35° +5 x - 10 = 180°
5x + 25° = 180°
5x = 180- 25
x = 155/5
x = 31°

< CBD = 4x = 4(31 ) = 124°

:)) maaf klu salah seperti itu caranya.