Can i have formula of calculating area

Answer 1

of what ?
circle pi r^2
square s^2
rectangle L w

general
integral of dy dx ?

Answer 2

Area of Parallelogram

Answer 3

Google is a great help.

http://www.google.com/#q=Area+of+Parallelogram+

Answer 4

base times height. It is the same as a rectangle with a triangle taken off one end and tacked to the other end. Draw it.