Explanation:
Since the envelope is a rectangle
Perimeter of a rectangle = 2l + 2w
where
l is the length
w is the width
Area of a rectangle = length × width
From the question
l = 4 inches
w = 8 inches
For the perimeter
P = 2(4) + 2(8)
= 8 + 16
We have the final answer as
24 inches
For the area
A = 4 × 8
We have the final answer as
32 inches²
Hope this helps you