Question

How would I go about finding the area of this polygon? Thanks in advance.

Answer 1

notice the picture below

all you really have  is a rectangle and a triangle
so...notice the dimensions for the rectangle
and keep in mind that area of a triangle is 1/2 bh

thus, get their areas, and sum them up, that's the area of the polygon

Answer 2

The easiest way to find the area of that polygon would be to imagine the evident rectangle and triangles in the picture. It is easier to find the area's of those shapes than that of an abstract shape. 
The formula for the area of a rectangle: A= l x w
The formula for the area of a triangle: A=1/2 bh
Plug your figures into the formulas, A= 7 x 5 =35  +     A= 1/2 (7x2)=7   = 42

The total area would be 42 units^2