Analytic geometry

You can find the length of the sides sing the distance formula:

√((x2-x1)²+(y2-y1)²)

(x2, y2) is a coordinate point

(x1, y1) is a coordinate point

Once you find the two points you are going to use, plug them in into the distance formula and solve for the distance

Then, find the area

 If you don't understand this, check this out:

https://web2.0calc.com/questions/halp-plz_12

It's the same question

I hope this helped!

Consider  the  following

Find  the  area of  EFGH  =   EF  x  FG   =   5 x 4  =  20       (1)

Then

Areas of  right triangles  EBA, AHD , DGC   and  BFC  =

(1/2)  ( 1 * 3  +  4 * 1   + 1 *3   +  4 * 1)  =   

( 1/2)  ( 3 + 4  +  3 + 4)

(1/2) ( 14)   =  

7         (2)

Area of   ABCD   =   (1)  - (2)  =   20  - 7  =    13