Answer:
d = 13
Step-by-step explanation:
Given:
m ∠ d = 27°
m ∠ a = 105°
t = 21°
Look at the picture I posted
Use sine law:
[tex]\mathrm{\dfrac{ sin\:a }{ A } = \dfrac{ sin\:B }{ b }}[/tex]
∠T = 180° - 27° - 105°
∠T = 48°
[tex]\mathrm{\dfrac{ sin\:48\° }{ 21 } = \dfrac{ sin\:D }{ d }}[/tex]
[tex]\mathrm{\dfrac{ sin\:48\° }{ 21 } = \dfrac{ sin\:27 }{ d }}[/tex]
Cross multiply
[tex]\mathrm{{d\:sin\:48\°} = { 21\:sin\:27\°}}[/tex]
Solve for d
[tex]\mathrm{d = \dfrac{ 21\:sin\:27\° }{ sin\:48\° }}[/tex]
Evaluate trigonometric functions in the problem
[tex]\mathrm{d = \dfrac{ 21 \times 0.453990499739547 }{ 0.743144825477394 }}[/tex]
Multiply 21 and 0.453990499739547 to get 9.533800494530487
[tex]\mathrm{d = \dfrac{ 9.533800494530487 }{ 0.74314482547394 }}[/tex]
Divide 9.533800494530487 by 0.743144825477394
[tex]\mathrm{d = 12.828993983}[/tex]
d = 13
Rounded to the nearest integer: 13
