Answer:
10.665 inches
Step-by-step explanation:
Lateral Surface Area of a square pyramid (4 isosceles triangles): For the isosceles triangle Area = (1/2)Base x Height. Our base is side length a and for this calculation our height for the triangle is slant height s. With 4 sides we need to multiply by 4
= 1/2 ? x 6
we divide 128 by 6
21.33/1/2 = 10.665