Answer:
Correct answer is [tex]C)\ 254\ m^{2}[/tex]
Step-by-step explanation:
As per the given diagram, we know the following details:
Height of the triangular pyramid is 14m.
Side of base = 10m
Height of Triangular base = 8.7m
Formula for surface area of triangular pyramid:
[tex]\text{Area = Area of Triangular base + 3 }\times\text{Area of side triangle}[/tex]
(Triangular base is shown in the dotted lines in the question figure.
The other 3 triangles are the side triangles.)
We know that,
[tex]\text{Area of a triangle = }\dfrac{1}{2} \times \text{Base} \times \text{Height}[/tex]
[tex]\Rightarrow \text{Required Surface Area = } \dfrac{1}{2} \times 8.7 \times 10 + 3 \times \dfrac{1}{2} \times 14 \times 10\\\Rightarrow \dfrac{1}{2}\times (87 + 3 \times 140)\\\Rightarrow \dfrac{1}{2}\times (87 + 420)\\\Rightarrow \dfrac{1}{2} \times 507\\$\approx$ 254 m^{2}[/tex]
Hence correct answer is [tex]C)\ 254\ m^{2}[/tex].
