Find the Surface Area box (3)(4)(5)

 $\begin{array}{r} h = & 3 \\ l = & 4 \\ w = & 5 \end{array}$

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 $l = 4$ , the width $w = 5$ , and the height $h = 3$ into the formula.

$2 \cdot 4 \cdot 5 + 2 \cdot 4 \cdot 3 + 2 \cdot 5 \cdot 3$

Step 3

Simplify each term.

Multiply $2 \cdot 4 \cdot 5$ .

Multiply $2$ by $4$ .

$8 \cdot 5 + 2 \cdot 4 \cdot 3 + 2 \cdot 5 \cdot 3$

Multiply $8$ by $5$ .

$40 + 2 \cdot 4 \cdot 3 + 2 \cdot 5 \cdot 3$

Multiply $2 \cdot 4 \cdot 3$ .

Multiply $2$ by $4$ .

$40 + 8 \cdot 3 + 2 \cdot 5 \cdot 3$

Multiply $8$ by $3$ .

$40 + 24 + 2 \cdot 5 \cdot 3$

Multiply $2 \cdot 5 \cdot 3$ .

Multiply $2$ by $5$ .

$40 + 24 + 10 \cdot 3$

Multiply $10$ by $3$ .

$40 + 24 + 30$

Step 4

Simplify by adding numbers.

Add $40$ and $24$ .

$64 + 30$

Add $64$ and $30$ .

$94$