I know the answer. But i don't understand how to get the answer. Answer is B.
If you know how to get the answer please tell me.

a net is a diagram that shows a “flattened” view of a solid. in a net, each face and base is shown with all of its dimensions. a net can also serve as a pattern to build a three-dimensional solid.

a pyramid is a three-dimensional object with a base that is a polygon and triangular faces that meet at one vertex.

" the net of a triangular pyramid consists of four triangles. the base here we are given of the pyramid is a equilateral   triangle, and the lateral faces are also triangles "

your answer is  

d.

196.5 m2

step-by-step explanation:

тнєу єα¢н яαи 32 мιℓєѕ

step-by-step explanation:

нσρє ι ¢συℓ∂ нєℓρ уσυ συт тσ∂α!