Find the Surface Area box (5)(3)(8)

 $\begin{array}{r} h = & 5 \\ l = & 3 \\ w = & 8 \end{array}$

Step 1

The surface area of a box is equal to the sum of the areas of each side of the box.

$2 \cdot (l e n g t h) \cdot (w i d t h) + 2 \cdot (l e n g t h) \cdot (h e i g h t) + 2 \cdot (w i d t h) \cdot (h e i g h t)$

Step 2

Substitute the values of the length $l = 3$ , the width $w = 8$ , and the height $h = 5$ into the formula.

$2 \cdot 3 \cdot 8 + 2 \cdot 3 \cdot 5 + 2 \cdot 8 \cdot 5$

Step 3

Simplify each term.

Multiply $2 \cdot 3 \cdot 8$ .

Multiply $2$ by $3$ .

$6 \cdot 8 + 2 \cdot 3 \cdot 5 + 2 \cdot 8 \cdot 5$

Multiply $6$ by $8$ .

$48 + 2 \cdot 3 \cdot 5 + 2 \cdot 8 \cdot 5$

Multiply $2 \cdot 3 \cdot 5$ .

Multiply $2$ by $3$ .

$48 + 6 \cdot 5 + 2 \cdot 8 \cdot 5$

Multiply $6$ by $5$ .

$48 + 30 + 2 \cdot 8 \cdot 5$

Multiply $2 \cdot 8 \cdot 5$ .

Multiply $2$ by $8$ .

$48 + 30 + 16 \cdot 5$

Multiply $16$ by $5$ .

$48 + 30 + 80$

Step 4

Simplify by adding numbers.

Add $48$ and $30$ .

$78 + 80$

Add $78$ and $80$ .

$158$