A boat leaves the dock and travels 9 miles due south, then 12 miles due west. Hence, the length of the boat from the dock will be 15 miles.
What is Pythagoras's Theorem?
If ABC is a triangle with AC as the hypotenuse and angle B with 90 degrees then we have:
[tex]|AC|^2 = |AB|^2 + |BC|^2[/tex]
where |AB| = length of line segment AB. (AB and BC are the rest of the two sides of that triangle ABC, AC being the hypotenuse).
A boat leaves the dock and travels 9 miles due south, then 12 miles due west.
Let x be the length of the boat from the dock.
From the Pythagoras' theorem
[tex]|x|^2 = |12|^2 + |9|^2 \\\\x^2 = 144 + 81\\\\x^2 = 225\\\\x = \sqrt{225} \\\\x = 15[/tex]
Hence, the length of the boat from the dock will be 15 miles.
Learn more about Pythagoras' theorem here:
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