Given pyramid with octagonal base. Image of the pyramid attached below:
We know the formula of Lateral Area of pyramid = [tex] \frac{1}{2} pl [/tex]
where p represent the perimeter of the octagonal base
and l represent the slant height of the pyramid.
109.9 = [tex] \frac{1}{2}*p*6.7 [/tex]
Solve for p
p = 32.81 cm
Perimeter of octagonal base (all sides are same) = 8*s
where s represent the side of octagon
8s = 32.81
Solve for s
s = 4.1 cm
Side of the octagon = 4.1cm (option D)