Answer:
532.79yards²
Step-by-step explanation:
Surface area of a pyramid = A + 1/Ph
A is the base area
P is the perimeter of the base
h is the height of the pyramid
Given the following
Height of triangular base = 17.3yards
Base of the triangle = 20yards
Height of prism = 12yards
Base Area = 1/2 × 20×17.3
Base Area = 10×17.3
Base Area = 173yd²
For the Perimeter P
Get the slant height using Pythagoras theorem
s² = (20/2)²+17.3²
s² = 10²+17.3²
s² = 100+299.29
s² = 399.29
s = √399.29
s = 19.98
Perimeter = 19.98+19.98+20
Perimeter = 59.96yards
Substitute
Surface Area = 173+1/2((59.96)(12)
Surface Area = 173+6(59.96)
Surface Area = 173+359.79
Surface Area = 532.79yards²
