ADOBE ILLUSTRATOR COREL DRAW AND MANY OTHER SOFTWARES ARE AVAILABLE FOR CREATING DESIGNS .THERE ARE MANY IN BUILT GRAPHICS IN THESE SOFTWARES .BUT IF YOU WANT TO CREATE SHAPES AS YOU WANT ,IT IS NOT DIFFICULT BUT VERY EASY WITH THE HELP OF THESE SOFTWARES .DRAWING DESIRED SHAPES ARE NOT POSSIBLE WITH PENCIL TOOL .YOU CAN DRAW ANY DEISED SHAPE WITH THE HELP OF PEN TOOL .

SELECT PEN TOOL FROM TOOL BAR

THEN  CLICK ON THE ART BOARD AND LEAVE THE MOUSE BUTTON IF YOU WANT TO DRAW AN STAIGHT LINE

IF YOU WANT TO CREATE A CURVED LINE HOLD DOWN THE MOUSE AND CREATE A DESIRED CURVATURE .

AFTER CREATING YOU LINE YOU CAN CONTINUE ON THE PATH BY CLICKING AGAIN

ADOBE ILLUSTRATOR CS4 HAS THE BEST PEN TOOL AND EASIEST IN USE