The length of the entire tunnel is 127.88 meters by using cosine law or formulae.
Here we can use the formulae of cosine when two sides a and b and angle between then is given we can apply it.
Let us take surveyor as point A
one end of the tunnel denoted by point B
other end of the tunnel denoted by point C.
The length of AB is 101 meters
length of AC is 120 meters.
Measure of angle at point A = 42° + 28° =70°
Now lets find the length of tunnel
=
=
=
=127.88 meters.
Hence the length of the entire tunnel is 127.88 meters.
You can find more about cosine law: brainly.com/question/28135764
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