Atea bag is shaped like a regular square pyramid. each leg of the base is 4 cm, and the slant height is 5 cm. what are the lateral area & surface area of the tea bag?

The lateral area of the tea bag is the sum of the areas of the four triangles.
                                    LA = 4 x (1/2)bh
Substituting,
                                     LA = 4 x (1/2)(4 cm)(5 cm) = 40 cm²
The surface area is the sum of the lateral area and the area of the base.
                               SA = LA + BA
                             SA = 40 cm² + (4 cm)(4 cm)   = 56 cm²