Question

Find the surface area of a cube having its sides equal to 8 cm in length.​

Answer 1

$\huge\boxed{\fcolorbox{red}{blue}{Answer}}$

The surface of a cube is composed of six (6) congruent faces, i.e, all 6 faces are the same size, and each face of a cube is a square. The area A of a square is given by the formula: A = s², where s is the length of each of the 4 congruent sides of the square.

Therefore, the surface area S of a cube is given by the formula:

S = 6s²

We're given that an edge of a cube is 8 cm, but all 12 edges of a cube are congruent, i.e., they all have the same length, in this case, 8 cm. The edges of a cube are formed by the intersections of the faces of the cube, but these same edges also function as the sides of the six (6) congruent square faces of the cube; therefore, the length s of each of the 4 congruent sides of each square face of the cube is: s = 8 cm; therefore, the surface area S of a cube with an edge of length 8 cm is:

S = 6(8 cm)²

= 6(8 cm)(8 cm)

= 48 cm(8 cm)

$\huge\boxed{\fcolorbox{red}{blue}{= 384 cm²}}$

Answer 2

Answer:

384 cm²

Step-by-step explanation:

The surface of a cube is composed of six (6) congruent faces, i.e, all 6 faces are the same size, and each face of a cube is a square. The area A of a square is given by the formula: A = s², where s is the length of each of the 4 congruent sides of the square.

Therefore, the surface area S of a cube is given by the formula:

S = 6s²

We're given that an edge of a cube is 8 cm, but all 12 edges of a cube are congruent, i.e., they all have the same length, in this case, 8 cm. The edges of a cube are formed by the intersections of the faces of the cube, but these same edges also function as the sides of the six (6) congruent square faces of the cube; therefore, the length s of each of the 4 congruent sides of each square face of the cube is: s = 8 cm; therefore, the surface area S of a cube with an edge of length 8 cm is:

S = 6(8 cm)²

= 6(8 cm)(8 cm)

= 48 cm(8 cm)

= 384 cm²