Then area of each shape can be find ina different form. Each figure have a formula to find the area.
For example
Trapezoid:
Where B1 is one of the bases and B2 the other base. h is the vertical height.
Triangle:
b is the base and h is the vertical height.
Regular polygon:
P is the perimeter of the regular polygon and a is the apothem (the distance for the center of the polygon to the mind-point of a side.