Triangle:
Base:  
Height:
Calculate Area

Rectangle:
Width:
Height:
Calculate Area

Square:
Side:
Calculate Area

Parallelogram:
Base:  
Height:
Calculate Area

Trapezoid (US):
Trapezium (UK):
Sum of length of two parallel sides:
          
Height:
Calculate Area

Ellipse:
Major axis/2:
Minor axis/2:
Calculate Area

Circle:
Radius:
Calculate Area

Sector:
Radius:              
Angle in radians:
Calculate Area