Raymond B. answered 05/07/20
Math, microeconomics or criminal justice
surface area = 336 = 4 times x (x=the surface area of each of 4 sides)
x=336/4= 84
each of the surface areas of the sides = one half times the base 12 times the slanted height.
Area of each = 84 = (1/2)12y where y= slanted height
y= 84/6 = 14 feet
each of the four sides form triangles 14 x 14 x12
the center of the bottom of the pyramid is half way, in the middle, a distance of 6 from the base on any of the 4 sides. This forms an upright right triangle of 6 x 14 x sqr(14^2 - 6^2) = 6x14xsqr160=6x14x4sq10=6x14x12.64
the slant is the angle formed between the base 6 and the side 14 which is the angle whose cosine = 6/14=3/7
Use the inverse trig function on a calculator to get about 64.6 degrees or a little over pi/3=60 degrees