Calculate Cuboid Width: Surface Area 122 cm² with Given Dimensions

Question

Look at the cuboid of the figure.

Its surface area is 122 cm².

What is the width of the cuboid?

00:00 Find the width of the box (W)

00:03 We will use the formula for calculating the surface area of a box

00:11 We will substitute appropriate values and solve for width W

00:24 We will divide by 2

00:36 We will isolate width W

00:50 This is the solution to the question

To solve the problem, let's recall the formula for calculating the surface area of a box:

(width*length + height*width + height*length) *2

Let's substitute the known values into the formula, and we'll denote the missing side as X:

2*(3*7+7*X+3*X) = 122

2*(21+7x+3x) = 122

2(21+10x) = 122

Let's expand the parentheses:

42+20x=122

Let's move terms:

20x=122-42

20x=80

Let's simplify:

x=4

And that's the solution!

4 cm