Elementary Geometry for College Students (7th Edition)

$60$ft$^2$
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$^2$