The perimeter is 38.4 inches
Answer:
<h2>(5x+4)(x-1)</h2>
Step-by-step explanation:

The formula required is tangent
Using the values they give you:
Length= 5cm
Width= 3cm
Height= 8cm
and using the formula:
length x width x height = 5 x 3 x 8 = 120 cm^3
The volume of the box is 120cm^3
It is x=8 because 13+7=20 and 28-20 would be 8 and that's the missing number.