First photo
Surface area of pyramid:
Perimeter * slant lenght/2 + Base Area (5*5)= (5*4)*12/2 = 20*12/2 = 240/2 = 120 in^2 + 25 in = 145 in^2
Second photo
Surface area of cone: Superficial area + base area
So lets find the superficial area pi*r*slant lenght
8*pi*13 = 104*pi = 326,56 cm^2
Find the base area = r^2*pi = 8*8*pi = 64*pi = 200,96 cm^2
Superficial area = 326,56+200,96 = 527,52 cm^2
Third photo
To find the slant height you have to do SurfaceArea/r*pi
Then find the slant lenght 243/7*pi = 243/21,98 = 11,05555
