Ambika02 wrote:
Hi Bunuel,
All the 5 triangles formed will have one angle=(360/5)=72 and the other two angles=(180-72)/2=54 each.the altitude of each triangle will bisect the base.So if we know the base=3 and the angles as 90,54,(72/2) can't we calculate the length of each side by trigonometry?If yes, then C should be the right answer.
Also, since the triangles are all equal , does that not mean that the slant height is equal to its base? and then use the below formula:
The surface area of a right pyramid can be calculated, using the following formula:
SA = B + 1/2( Ps ), where B is the area of the base, P is the perimeter of the base, and s is the slant height