Answer: 219.52 inch^2
Step-by-step explanation:
Given the dimensions of rectangular papaerboard:
Length = 20inches
Width = 16inches
Area of rectangle = Length × width
Area of rectangle = 20 × 16 = 320 in^2
Area of a circle = pi*r^2
Therefore, area of semicircle = (pi*r^2) / 2
Diameter of circle = width of rectangle = 16 inches
Radius = diameter / 2 = 16 /2 = 8inches
Therefore, area of semicircle = (pi*8^2) / 2
= (3.14 × 64) / 2
= 200.96 / 2
= 100.48 inch^2
Therefore, area of paperboard left :
Area of rectangle - area of semicircle
320 - 100.48
= 219.52 inch^2
167.462 because you can round up the 4 to a 5 because the second number is 5 or up.
Answer: 
Step-by-step explanation:
The perimeter of a rectangle can be calcualated with this formula:

Where "l" is the lenght and "h" is the height.
The area of a rectangle can be found with this formula:

Where "l" is the lenght and "h" is the height.
In this case we know that:

Therfore, we can susbsitute them into
and solve for "h" in order to find its value:

Find two number whose sum is 3 and whose product is -40. These are -5 and 8. Then, factorizing, we get:

The positive value is the height. Then:

Since the length is 3 centimeters greater than its height, we get that this is: Then:

Substituting values into
, we get that the perimeter is:
