Question: how to find the surface area of a frustum of a square pyramid?
Answer: are trapeziums; the distance between the parallel sides of this trapeziums is the slant height of the frustum of the pyramid. = ½ × (perimeter of the lower face + perimeter of the upper face) × l. = Area of the slant faces + S₁ + S₂; (C) Volume of the frustum = 1/3 × (S₁ + S₂ + √ S₁ S₂) × h.