Asquare pyramid is made up of a base with a side length of 10 inches and faces that are triangles with a height of 12 inches. what is the surface area of the square pyramid?

a. 120 square inches
b. 125 square inches
c. 240 square inches
d. 340 square inches

I believe it is A, 120 square inches.

(A)

Step-by-step explanation: 120 square inches.

hello from mrbilldoesmath!

answer:

(7 x + 6 y) (49 x^2 - 42 x y + 36 y^2)

discussion:

the trick is to recognize that 343 = 7^3 and 216 = 6^3 and, in general,

a^3 + b^3 =   (a + b) (a^2 - a b + b^2).

in our case

343x^3+216y^3   =   (7x)^3 + (6y)^3

so take a = 7x and b = 6y in the above equation to get the answer.

you,

mrb