Answer
Find out the what is the length of CD , AC .
To prove
By using the trignometric identity
[tex]sin B = \frac{Perpendicular}{Hypotenuse}[/tex]
As in ΔABC
∠ B = 30° , AB= 10 cm
put in the trignometric identity
[tex]sin 30^{\circ} = \frac{AC}{10}[/tex]
As
[tex]sin30^{\circ} =\frac{1}{2}[/tex]
[tex]\frac{1}{2} = \frac{AC}{10}[/tex]
[tex]AC = \frac{10}{2}[/tex]
AC = 5cm
Now in the ΔADC
[tex]tan D^{\circ} = \frac{Perpendicular}{Base}[/tex]
∠ D = 25° , AC = Perpendicular = 5 cm
[tex]tan 25^{\circ} = \frac{5}{CD}[/tex]
tan 25 ° = 0.46630765815 (approx)
[tex]CD = \frac{5}{0.46630765815}[/tex]
CD = 10 .7cm ( approx )
Option (C) is correct .
