Question

I'm horrible at this so can I please get help, the rest says "solve for a. a=


`a = √(?)`
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Answer 1

a =
`√(63)`

Explanation:

Using Pythagoras' identity in the right triangle.

The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is

a² + 9² = 12²

a² + 81 = 144 ( subtract 81 from both sides )

a² = 63 ( take square root of both sides )

a =
`√(63)`