Take a piece of paper and a pencil.
Put your pencil on the paper and draw anything you want, with the following conditions:
a simple closed plane curve 
a simple plane curve, that is not closed 
a closed plane curve, that is not simple 
a plane curve that is not simple and not closed 
not a plane curve 
(it is drawn on both the front face and the top face) 
When you are asked for the ‘area’ of a simple closed plane curve, this means the area inside the curve.
For example, the area of a rectangle is the area inside the rectangle, and the area of a triangle
is the area inside the triangle.
Whereas area measures the space ‘inside’ a figure, we can also ask about the distance ‘around’ a figure:
Quite a mouthful! Probably more than you want to hear right now!
The definition looks simpler if we specialize it to polygons:
Note that your teacher might ask you to ‘trace a perimeter’—that is, run your finger (or pencil) along a curve.
Or, your teacher might ask you to ‘shade an area’—that is, shade the region inside a simple closed plane curve.
Perimeter is measured using units of length.
Consequently, these are all valid units for perimeter, with their common abbreviations:
Every unit of length has a corresponding unit of area, created as follows:
$\,\text{length} = 1\text{ blah}\,$  $\,\text{area} = 1 \text{ square blah} = 1{\text{ blah}}^2\,$ 
a unit of length  a unit of area 
Here are some valid units for area, with abbreviations:
Here are some basic formulas:
AREA OF A RECTANGLE:
A rectangle with length $\,\ell \,$ and
width $\,w\,$ has area $\,A\,$
given by $\,A=\ell w\,$.
AREA OF A SQUARE:
A square with sides of length $\,\ell \,$ has area $\,A\,$
given by $\,A=\ell^2\,$.
PERIMETER OF A RECTANGLE:
A rectangle with length $\,\ell \,$ and
width $\,w\,$ has perimeter $\,P\,$
given by $\,P=2\ell + 2w\,$.
PERIMETER OF A SQUARE:
A square with sides of length $\,\ell \,$ has perimeter $\,P\,$
given by $\,P=4\ell\,$.
On this exercise, you will not key in your answer. However, you can check to see if your answer is correct. 
PROBLEM TYPES:
