Respuesta :

The answer is 9cm

SA = r + r 2

452.16 m 2 = (3.14)(6 m)(x) + (3.14)(6 m) 2

452.16 m 2 = (3.14)(6 m)(x) + (3.14)(36 m 2)

452.16 m 2 = (18.84 m)x + 113.04 m 2

339.12 m 2 = (18.84 m)x

18 m = x

Answer:

Option D. 9 cm

Step-by-step explanation:

Surface area of the given figure is S = 243 cm² and we have to find the slant height.

We can see this figure comprises of 1 square and 4 triangles.

Let the slant height of the given triangles is L.

So area of one triangle = [tex]\frac{1}{2}(Slant height).(Base)[/tex]

and the area of square = side² = 9² = 81 cm²

Now surface area of total figure = Area of square + 4×(area of a triangle)

[tex]243=9^{2}+\frac{4}{2}(9.L)[/tex]

243 = 81 + 2×9L

18L = 243 - 81 = 162

[tex]L=\frac{162}{18}[/tex]

L = 9 cm

Therefore Option D. 9 cm is the correct answer.