PLEASE find SA Find the surface area to the nearest tenth. (Only round on the very last step). SA =

885.2m²

Step-by-step explanation:

a is the side length of the square at the base

h is the height of the pyramid

Given

a = 18m

Get the height using the pythagoras theorem

h² =18²-9²

h² = 324 - 81

h² = 243

h = √243

h = 15.5884m

Area of the triangle = 1/2 * 18 * 15.5884

Area of the triangle = 9 * 15.5884

Area of the triangle = 140.2956m²

Area of the 4 triangles = 4(140.2956)

Area of the 4 triangles = 561.1824m²

Base area = 18 * 18

Base area = 324m²

Total surface area = Base area + Area of the 4 triangles

Total surface area = 324 + 561.1824

Total surface area = 885.1824

Total surface area = 885.2m² (to the nearest tenth)