\( \definecolor{colordef}{RGB}{249,49,84} \definecolor{colorprop}{RGB}{18,102,241} \)
A garden is in the shape of a semi-circle with diameter \( x \) meters.
Find the area \( A \) of the garden in terms of the diameter \( x \) of the semi-circle.
\( A = \)
\(\text{m}^2\).