From the diagram, the required length of the entire tunnel is (m + n) meters
In triangle ADC,
opposite = m
hypotenuse = 340
[tex]\begin{gathered} \sin \text{58 =}\frac{m}{340} \\ m\text{ = 340 x sin58} \\ m=288.336m \end{gathered}[/tex]
In triangle BCD,
opposite = n
Hypotenuse = 193
[tex]\begin{gathered} \sin 21=\frac{n}{193} \\ n=193\sin 21 \\ n=69.165m \end{gathered}[/tex]
The length of the tunnel is
288.336m + 69.165m
=357.501m
=357.5m ( nearest tenth)
The answer is 357.5m ( nearest tenth)
