9514 1404 393
Answer:
10 meters
Explanation:
You recognize that the ratio of leg lengths of the right triangle involved is ...
6 : 8 = 3 : 4
You know that any right triangle with leg lengths 3 and 4 has a hypotenuse of 5. The ladder will need to be in the same ratio:
3 : 4 : 5 = 6 : 8 : 10
The ladder needs to be 10 meters long.
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In case you don't remember that (3, 4, 5) is a "Pythagorean triple," you can figure the length using the Pythagorean theorem.
6^2 +8^2 = hypotenuse^2
36 +64 = 100 = hypotenuse^2
hypotenuse = √100 = 10 . . . . required ladder length in meters