if you have a 10ft ladder placd leaning against the wall,and the ladder is 6ft from the wall.how high does the ladder reach on the wall?

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6

Pythagorean theorem:

a^2 + b^2 = c^2

here you are looking for a so..

a^2 + 6^2 = 10^2

a^2 + 36 = 100

100 - 36 = 64

square root of 64 is 8

a= 8ft