Answer:
[tex]d = 340.7m[/tex]
Step-by-step explanation:
See attachment for question illustration
From the attachment, we have:
[tex]AB = 125m[/tex]
[tex]<A = 41.6[/tex]
[tex]<B = 124.3[/tex]
Required
Solve d
First, we need to calculate <C
[tex]<A + <B + <C = 180[/tex] --- angles in a triangle
[tex]41.6+ 124.3 + <C = 180[/tex]
[tex]165.9+ <C = 180[/tex]
Make <C the subject
[tex]<C = 180 - 165.9[/tex]
[tex]<C = 14.1[/tex]
Next, we apply Sine's law to solve for d
[tex]\frac{A}{Sin\ A} = \frac{B}{Sin\ B} =\frac{C}{Sin\ C}[/tex]
In this case:
[tex]\frac{d}{Sin\ 41.6} = \frac{125}{Sin\ 14.1}[/tex]
Make d the subject
[tex]d = \frac{125 * sin\ 41.6}{sin 14.1}[/tex]
[tex]d = \frac{125 * 0.66392621265}{0.24361501178}[/tex]
[tex]d = \frac{82.9907765812}{0.24361501178}[/tex]
[tex]d = 340.663639629[/tex]
[tex]d = 340.7m[/tex]
Hence, the base of the lake is approximately 340.7m
