Answer:
• let's first consinder triangle ADC
• from trigonometric ratios:
[tex] \hookrightarrow \: { \rm{ \tan( \theta) = \frac{opposite}{adjacent} }} \\ [/tex]
→ theta is the angle CAD
→ opposite is 16
→ adjacent is 12
[tex]{ \tt{ \tan( \theta) = \frac{16}{12} }} \\ \\ { \tt{ \theta = { \tan }^{ - 1}( \frac{16}{12} ) }} \\ \\ { \underline{ \tt{ \: \: \theta = 53.1 \degree \: }}}[/tex]
Then let's find the angle BCD
[tex]{ \tt{ \angle BCD + \angle CAD = 90 \degree}} \\ { \tt{\angle BCD + 53.1 \degree = 90 \degree}} \\ { \underline{ \tt{ \: \: \angle BCD = 36.9 \degree \: \: }}}[/tex]
• from trigonometric ratios:
[tex]{ \rm{ \tan( \theta) = \frac{opposite}{adjacent} }} \\ [/tex]
→ theta is 36.9°
→ opposite is DB
→ adjacent is 12
[tex]{ \tt{ \tan(36.9) = \frac{DB}{12} }} \\ \\ { \tt{DB = 12 \times \tan(36.9) }} \\ \\ { \tt{DB = 12 \times 0.75}} \\ \\ { \rm{answer : \: { \boxed{ \rm{ \: \: DB = 9 \: \: }}}}}[/tex]