we know that lateral area=3*[area of a equilateral triangle] Applying the law of sines to calculate the area of a equilateral triangle Area=(1/2)*a*b*sin C a=4 b=4 C=60 degrees area equilateral triangle=0.5*4*4*sin 60-----> 0.5*4*4*√3/2---> 4√3 units² lateral area=3*[4√3]----> 12√3 units²