Answer
$60$ft$^2$
Work Step by Step
To obtain the slant height , which is the height of the side, solve for the right triangle that has legs of lengths 3 (half of the base length) and 4.
$3^2+4^2=s^2$
slant height $=5$ ft
Multiply the slant height and half the base length to get the area of the side.
$A=3(5) = 15$ft$^2$
Multiply this by four to get the lateral area:
$15(4)=60$ft$^2$
