Laws of Cricket 1947 Code (Fourth Edition) - Law 9
The bowling crease shall be in line with the stumps; 8 feet 8 inches in length; the stumps in the centre; with a return crease at each end at right angles behind the wicket. The popping crease shall be marked 4 feet in front of and parallel with the bowling crease. Both the return and popping creases shall be deemed unlimited in length.
Note on Law 9
1. The distance of the popping crease from the wicket is measured from a line running through the centre of the stumps to the inside edge of the crease.
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