mathematics – For Pi Day, which expression is larger?

Without using the square root key or other root key on a calculator,
determine which side is larger.

$\pi \ \ \ \text{or} \ \ \ \sqrt{63} – \sqrt{23}$

You may use the squaring key $ \ X^2, \ $ parentheses, and the $ \ \pi \ $ key. You may
use an approximation for
$ \ \pi \ $ equal to $3.14159$ if you would like. You may not use the exponent key $X^Y$.