Hi Chandra
you want to create a pattern line which you apply to an element (you can apply a pattern to any 2D element) or in this case the circle.

Please go to Modify menu then choose Draft and Reshape surface elements. Follow the prompt line which will ask you to select the element which you wish to copy. Select anywhere on the hatched element. Then from the Dialog Line toolbar (can be docked at the prompt line) turn the Outline Auto-detect ON. Now click inside your curved area and press Esc and your pattern should have applied itself to your curved element. Here you have extended your pattern on a 2D element.

You also could have choose Hatching turned the option Outline Auto-detect ON (again found in the Dialog Line toolbar)then click in the curved area. The hatching will be applied. In this case, you have created 3 element areas with hatching applied.

Wendy