Given
Slant height 0.75 foot
Perimeter 1.2 feet equilateral base
Area 0.07 sq foot
Procedure
This is an example, now let apply to the problems
Area of base = 0.07 sq ft
Area of face = 1/2*0.4*0.75 = 0.15 sq ft
Total
3*0.15 + 0.07
0.52
The total area would be 0.52 sqft