a) The known values are ...
• the edge length of the square pyramid base is 6 cm
• the slant height of the square pyramid faces is 12 cm
b) The surface area is the sum of the area of the base and the area of the four triangular sides. The area of a triangle is half the product of base length and height (slant height, in this case).
A = b² +4*(1/2)*bh = b(b +2h)
Substituting known values, we have ...
A = (6 cm)*(6 cm +2*12 cm)
c) A = (6 cm)*(6 cm +24 cm) . . . . order of operations: multiplication inside parens
A = (6 cm)*(30 cm) . . . . . addition inside parens
A = 180 cm² . . . . . . . . . . multiplication
The area of the pyramid is 180 cm².