Question

SERIOUS HELP ONLY. (Use Special Right Triangles to Determine the Surface Area of a Regular Pyramid - Geometry).

What is the surface area of this square pyramid?
Round your answer to the nearest tenth.

122.2 yd²

192.8 yd²

244.4 yd²

513.3 yd²

NOTE: Image not drawn to scale.

Answer 1

192.8 yd²

Explanation:

Answer 2

Option B

Explanation:

a=side of square=8.4

h = height of the triangle =
`1/2(8.4) sin 60 = 2.1√(3)`

Each triangle on 4 sides would be equilateral because one angle is 60 and isosceles.

Side of triangle s = 8.4

base area =
`a^2 = 70.56\\`

Area of each equilateral triangle =
`√(3) (s^2)/(4) =17.64√(3)`

Hence surface area = base area +4(area of each triangle)

`= 70.56+17.64√(3)(4)\\=192.769\\=192.8` square yards

Hence option B is right answer