First is to understand the terms. Lateral area is the surface area of a 3D figure, excluding the area of any base.
Laterial Area (L.A.) of a right cone = pi*radius*slant height
radius = 1/2 * diameter
L.A. = pi*(1/2)*(4)*(15)=30*pi
the formula for this is pi*r*rt(r^2 + h^2). If the diameter is 4, then the radius is 2. If the slant height is 15, then to get the real height we use the Pythagorean Theorem and get rt(221). So the lateral area is pi*2*rt(2^2 + (rt221)^2)...= 2pi*rt(225) = 30pi = 94.248 meters squared which is rounded to 94 meters squared.