Answer:
x = 18
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
x² + 9² = 27²
x² + 81 = 729 ( subtract 81 from both sides )
x² = 648 ( take the square root of both sides )
x =
= 18
← exact value
x ≈ 25.5 ( to 1 dec. place )