make pizza.sh clean up after itself

pizza.sh

@@ -26,7 +26,7 @@ while getopts ":hf:" option; do
 done
 
 function panarea {
-	AREA=$(echo "3.1415926535*($DIAM/2)^2" | bc)
+	AREA=$(echo "3.1415926535*($DIAM/2)^2" | bc -l)
 	SIZE=$(echo $AREA*$FSI | bc)
 	calcratio
 }
@@ -39,6 +39,13 @@ function calcratio {
 		grep 'ratios' -A 8 pizza.txt | sed /\\[*.\\]/d | cut -f 1 | sed $LABEL'!d'
 		echo $RATIO*$SIZE | bc
 	done
+	# cleanup
+	unset LABEL
+	unset RATIO
+	unset SIZE
+	unset FSI
+	unset AREA
+	unset DIAM
 }
 
 case $1 in