Answer:
c. 105 yd^2.
Explanation:
First find the slant height (h) of each of the triangular walls:
tan 60 = h / 3.1
h = 3.1 tan 60
= 5.369 yds.
Area of each side = 3.1* 5.369
= 16.645
Total surface area of the pyramid
= 4 * 16.645 + 6.2^2
= 105.02 yd^2.