Classify the following as linear,quadratic,or cubic polynomial: $x^{2}-9x+14$.

(B) The degree of a polynomial is the highest power of the variable present in the expression.
For the given polynomial $x^{2}-9x+14$,the highest power of the variable $x$ is $2$.
$A$ polynomial of degree $2$ is called a quadratic polynomial.
Therefore,$x^{2}-9x+14$ is a quadratic polynomial.