Question

Pls help me thank you

Answer 1

140.4ft^2

Explanation:

since all four sides are equilateral triangles, you only need to find one triangle and multiply by 4.

area of triangle = 0.5×base×height = 0.5×7.8ft×9ft =35.1ft^2

surface area of pyramid= 35.2ft^2 × 4 = 140.4ft^2