Here's why:
* The "a" in "panel" has a short "a" sound, similar to the "a" in "cat" or "hat".
* Long vowel sounds are typically represented by a single vowel followed by a silent "e" at the end of a word or by a vowel digraph (two vowels together). For example, "pane" has a long "a" sound.
Therefore, the "a" in "panel" is a short vowel sound.