Answer: ∠BDA = 21; CB = 30
have:
sin ∠BDC = [tex]\frac{4x+6}{BD}[/tex]
sin ∠ADB = [tex]\frac{7x-12}{BD}[/tex]
because ∠BDC = ∠ADB => sin ∠BDC = sin ∠ADB
=> [tex]\frac{4x+6}{BD}=\frac{7x-12}{BD}[/tex]
=> 4x + 6 = 7x -12
<=> 3x = 18
<=> x = 6 => CB = 4.6 + 6 = 30
Step-by-step explanation:
