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5.2

Step-by-step explanation:

Formula for any right triangle is a^2 + b^2 = c^2

So plug in the values and you get:

a^2 + 3^2 = 6^2

convert the squared numbers and you get:

a^2 + 9 = 36

subtract 9 from both sides

9 = 36

-9 = -9

you get:

a^2 = 27

we can't have a squared number as our answer, so we find the square root of both.

a^2 cancels out and you get:

a = 5.2 (simplified and rounded to nearest tenth)

step-by-step explanation: