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12 votes
12 votes
A 12 foot ladder leans against a wall so that the base of the ladder is 7 feet from the wall. How high up on the wall will the ladder reach? Round to the nearest hundredth of a foot.

User Arifa Chan
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3.2k points

1 Answer

16 votes
16 votes
Answer 9.75 ft
Reason
Using the Pythagorean theory,
a^2 + b^2 = c^2 (the hypotenuse)
Since we know the diagonal measurement (the hypotenuse) we will call c=12
We know one leg is 7, so we will call b=7
Now we will solve for “a”
Changing the equation to subtract
c^2 - b^2 = a^2
Substitute in our numbers
12^2 - 7^2 = a^2
144-49= a^2
95 = a^2
Take square root of both sides

9.746 = “a” the unknown length
Round to nearest hundredth
9.75
User Bob Van Luijt
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2.8k points