“The penalty area or 18-yard box (also known less formally as the penalty box or simply box) is an area of an association football pitch. It is rectangular and extends 16.5m (18 yd) to each side of the goal and 16.5m (18 yd) in front of it. Within the penalty area is the penalty spot, which is 11m (12 yd) from the goal line, directly in-line with the centre of the goal. A penalty arc (often informally called ‘the D’) adjoins the penalty area, and encloses the area within 9.15m (10 yd) of the penalty spot. It does not form part of the penalty area and is only of relevance during the taking of a penalty kick, when any players inside the arc are adjudged to be encroaching. … Previously, penalty areas extended the width of the field, but were reduced to their current dimensions in 1901. …”
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