Respuesta :

Answer:

The answer to your question is the letter D.

Step-by-step explanation:

Data

∠A = 30°

∠C = 90°

BC = 12 ft

Process

1.- Calculate ∠B using the fact that the sum of the internal angles in a triangle equals 180°

                  ∠A + ∠B + ∠C = 180°

-Substitution

                  30 + ∠B + 90 = 180

-Solve for ∠B

                  ∠B = 180 - 90 - 30

-Result

                  ∠B = 60°

2.- Calculate the length of AC using the trigonometric function tan.

              tan A = BC / AC

-Solve for AC

              AC = BC / tan A

-Substitution

              AC = 12 / tan 30

-Result

            AC = 20.784 ft

3.- Calculate AB using the trigonometric function sin.

            sin 30 = BC / AB

-Solve for AB

            AB = BC / sin 30

-Substitution

            AB = 12 / sin 30

-Result

            AB = 24 ft