Find m angle a
a
10
b
20
c
16
d
14

  D.  14°

Step-by-step explanation:

The Law of Sines tells you sides are in proportion to the sine of the opposite angle:

  sin(A)/BC = sin(B)/AC

  sin(A) = BC/AC·sin(B)

  A = arcsin(BC/AC·sin(B)) = arcsin(7/28·sin(75°)) ≈ 13.974° ≈ 14°

Option A

Distance of each boat from light house is approximately 20 miles.

Solution:

The diagram of this question is attached below

In the attached figure A and B represents position of two boats and C represents position of light house.

Given that CA = CB and  

So triangle ABC is isosceles triangle with angle

 [Angle opposite to equal side CA and CB]

[Angle sum property of triangle]

Construct a median CE on AB,

AE = EB  [ Since CE is median]

In triangle AEC,

Hence AC that is distance of each boat from light house is approximately 20 miles.