Find the area of a semicircle ether enter an exact number or use 3.14 for pie and enter your answer as a decimal

(π/2)r²

Step-by-step explanation:

The formula for the area of a circle of radius r is A = πr².  Thus, the formula for the area of a semicircle of the same radius is A/2 = (π/2)r².  For a numerical answer you'll need to specify the radius.  

Note:  π = Greek letter pi; "pie" is a dessert, inappropriate here.  :)